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Why Does My Network Connection Drop Every so Often?


Why does my network connection drop every so often?

There are many possible reasons so I’ll focus a common one: confused network auto-speed detection. Most contemporary network cards, hubs, and routers attempt to automatically determine the speed of each network connection. Sometimes they get it wrong.

Most home and office networks run at either 10 or 100 megabits per second (mbs). Just how the network devices tell the difference varies from one device to the next. Most will also monitor the speed continuously just in case it changes. That means that if the device is going to make a mistake it could happen at any time. And that can look like anything from really poor network performance to a previously working network connection suddenly dropping.

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The most common auto-detect confusion happens when the devices at both ends of a network connection are trying to auto-detect at the same time. The detection mechanisms can actually conflict with each other and cause one side to get it wrong. It’s not as common but the detection algorithm can also be affected by the actual data going across the wire, or electrical noise.

In most cases, especially on a small business or home network, you know what your network speed is and the autodetect functionality is unnecessary. It’s typically easy to turn off auto-speed detection on your network card and that’s often a good step to take when analyzing network problems.

You’ll first need to know what speed the connection should be at. That’s usually the fastest speed supported by your computer and the device at the other end of the network cable it’s plugged into. If your computer is connected to a router that router’s documentation should tell you. If you’re connected directly to a DSL modem the speed is typically 10mbs. If you’re not sure, select 10mbs as most faster devices are also auto-detecting and will match your selection.

The specific settings for auto-detection will vary slightly based on the manufacturer of your network card. Fortunately the location of those settings is consistent and the terminology used is fairly common.

To turn off network speed auto-detection:

  • Select Network Settings, either from your Start menu or from within Control Panel.
  • Right click on the connection that corresponds to your network card, and select Properties.
  • In the dialog that results, click on the Configure… button immediately below the “Connect using…” item that shows your network card.
  • In the dialog that results, click on the Advanced tab.

This is where things vary based on your network card. In the left-hand list will be a series of properties that can be adjusted. Look for a setting similar to “Speed”, or “Link”, or perhaps “Media Type”. Click on that, and the right-hand “Value” dropdown list will probably have something similar to “Auto”. If you click on that drop-down list and options include entries that look like “10mbs”, “100mbs”, and so on, you’ve found the right item. Change the setting from auto by clicking on the specific speed you’ve determined you want the network card to run at, and press OK (If the setting also includes a full/half duplex selection, full is normally correct.)

Windows should apply your setting change immediately.

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68 comments on “Why Does My Network Connection Drop Every so Often?”

  1. after removal of svchost iam facing problem in office 2000 that is when i open any file from look in it takes lot of time to open the look in drop down list.Please help me out in this issue

  2. i am working the office there are some systems suddenly network droped everything ok(hub,network cards,systems,swithcs..)ping is not accepted after 10 minutes network is is the problem same problem last week is comming.what is the solution.

  3. We have an existing networks of 24 workstations, and three 8-port hubs. recently, a 24 port SWITCH was acqired. But the problem is that, some network cards that have both 10Mbs/100Mbs are not responding to the network, though the switch is 100Mbs. What could be the problem?

  4. we have 22 computer, and another 19 computer fromthe other office we are connected thru VPN, my problem was the windows messenger frequently drop connection when idle even in the same vicinity.

  5. I have 15 computers hooked up to a network switch that is a gigabit. 3 computers, hooked to the same switch, are only 100T.

    If I use this method, are there any problems connecting to the machines that are 100T? If so, should I select all 100T?

    Also…the computers that are 100T actually have 1000T cards, but are limited by the additional network they are in. those machines have two network cards. Can they be set to 1000T and still work on a 100T network?

  6. Thank you for solution proffered on Feb 18, 2005. However, how can I increase the speed of my network from 10mbs to 100mbs without having any problem?

  7. I have a laptop on the network that is already set to 100full which id the network speed of the business. The laptop has ICQ amd AIM, two instant messaging programs running at the same time. Every five to twenty minutes, they both state that you have signed of and signed back on. This is very annoying because then all of the old messages pop up as new messages. This also often prevents me from sending messages out to co-workers. I have also disabled all NIC card binding protocols except for tcp/ip, and the two network sharing things. E-mail me any idea’s you may have.

  8. I want to know why the network connection suddenly goes off and on. I woke up this morning and accessing the network became a problem (“Network cable is now connected” then almost immediately i get “Network cable disconnected”) yet i used it just before sleeping. It was off for hours untill there was an electricity Power problem and on restoring the Electricity the network suddenly beams up that “Network cable is now connected”.

    I guess the network was reset after the power outage. What is really responsible for this network behaviour?


  9. Why does our network connection drop every so often when one of us attempts to log in to windows messenger. Actually some of us are now using msn messenger but still our network connection goes down everytime we log in to msn messenger while there are others when they log in to msn messenger our network connection is not affected at all. Hope you can give me an answer to this thanks…. pls email me…!

  10. Hi Leo, I use MSN Messenger lots and 1 day i went to log on and it let me logon for like 10 seconeds then a little popup comes up from the bottom left of the screen saying that a local area connection is unpluged and nomatter how many tries i do this it keeps happening but for my sister on her email account it works…. Im really frustrated so plz email me back for some help…

  11. Hi Leo…
    Thanks for the good advice… I have read a few people talking about msn messenger.. i too have the same problem of it dropping out randomly.
    Could ouy please tell me why.. and how to fix this?

    Thank you

  12. Hi Leo,

    As you send in the article above, it’s one possibility. My situation seems to be different from what you’ve described. My connection was fine until last Friday when it started dropping out approximately every half an hour, sometimes more sometimes less. When it drops out I cannot connect to anything over the network, other machines, email, internet, etc. If I leave it long enough the connection will restore itself, or I have to either reboot my machine or disable then enable the network connections. I’ve run two virus scanners on my computer, and tried the connections with both the firewall on and off. I’ve tried the repair connection option, the loacl area connection says it’s repaired, the 1394 connection says it’s not TCP/IP and can’t repair it. Can you offer any suggestions on what might be causing this and how to fix it?


  13. Hi, I have similar problem as Rod ^^. (Only) 1 of 2 comps (DSL modem) gets dropped randomly, it can be an one or ten hours. I can disable and then enable my “local area connection” (or reboot) to re-start the internet. Coincidently or not with Rod this problem started at end of June. I’ve run Windows update, Norton, and Ad-aware/SpyBlaster. I don’t use MSN/ICQ/AIM. TIA

  14. i have been told that a xp to 98 internet connection will only last 15 minutes because xp is configured to that time only but have been told thet the default can be changed .’
    Any thruth in this?
    awaiting your replies

  15. 100mbs means you are connected at 100 megabits per second – it’s just telling you how fast your connection is. That’s not a problem.

  16. If your network is dropping you – you need to turn off power managment on the nic card – xp and 2000 come with it auto on. From the local are network properties hit the configure on the nic card – hit power manamgment tab – and remove the tic from all the pc to turn off device to save power.

  17. I just installed a Linksys Wireless G router so that I can take my laptop anywhere in the house and still be able to connect to the internet. Setup and configuration was successful, and my wireless connection is fine for about 10 minutes or so, but then I get a pop up box that says “can’t connect to any of your preferred wireless networks.” I can wait a little while and refresh the wireless connection, but that’s annoying. How can I fix this?

  18. My situation seems to be similair to the guy who posted this My connection was fine on one comouter at home and the other it is not – it started dropping out approximately every half an hour, sometimes more sometimes less. When it drops out I cannot connect to anything over the network, other machines, email, internet, etc. I cna not enble the card, sometimes i can not see any networks weither. I have to either reboot my machine but then it loss it again.
    I’ve run two virus scanners on my computer, and tried the connections with both the firewall on and off. I’ve tried the repair connection.

    One computer works on the wireless network and one does not after having used both for over a year.

  19. I was having similar problems where every hour or so, my connection would go down for a short time and come back up.

    In my case, the Event Log would have a DHCP error saying it was unable to renew the lease and then some TCP/IP errors.

    I came across an article today that has fixed my problem – it involves editing the registry – so as everyone always says – be careful and backup first.

    Find this key :


    then ADD a new DWORD called DisableDHCPMediaSense
    with a value of 1

    I hope this helps.

  20. I have a network of 200 computers.Some of the computers are switching automatically to 10mbps randomly even though the network speed is 100mbps.
    Manually selecting the speed from the NIC properties
    does not help as connection keeps on showing 10mbps connection speed even though the link speed is set at 100 full duplex.During this time the computer is not able to ping any device on the network by IP address or hostname ..However if I swich off that computer for an hour or so everything is back to the normal…Any ideas why it might be happening…

  21. I tried to do what you said, and my device driver became disabled, which in turn scared me half out of my wits. What could have gone wrong? Perhaps you should also include troubleshooting information to get us back on track, just in case. SO LAME!!! I won’t buy you a latte, but I will buy you a computer manual.

  22. Mr. Leo,

    Im using a wireless broadband connection in Philippines ( SE Asia ), After my last activation of my internet ( You need to pay every month to reactivate your internet in Philippines ) My internet is dropping every 5-10mins, I dont know why. It stopped me from playing RO and using MSN because I always get disconnected ( In my game ragnarok, I lag for about 2-3mins and then DC ). I already did your instructions, I changed the auto-detect to 100mbps. What should I do now? I need a abetter thing.

  23. Good article. I was experiencing this problem.

    m = milli
    M = mega

    All the references to mbps should be Mbps

    b = bit and correctly used in article
    B = byte


  24. Like the article states; there are many possible reasons but when troubleshooting network problems it’s always a good idea to work through the OSI model to help identify the problem. i.e. start with the Physical layer and work your way through the layers. Most problems occur at the physical layer with bad cabling/termination the chief reason.

    One other point that you should all know is that a network will only be as fast as the slowest component within it. So if a PC has a virus or other pests like spyware then the NIC in the infected PC will drop its link speed (LLC) or even stop accepting frames (packets) altogether as the PC can’t process them as its too busy processing the virus/spywares’ commands. Another related reason is a DOS style attack that floods the network to a standstill.

    Also, just because your security software can’t find a virus it doesn’t mean there’s no infection!

    Oh and shame on you to the person who looks after a network of 200 computers and doesnt know what to do. May I suggest that you seek employment in another industry?

  25. I changed the speed to full Duplex 100mbs and I think more importantly, switched off the save power by switching off this device in the Power Management configuration of my network connection. I noticed an immediate improvement, but only time will tell whether the drop in the connection is eliminated.

  26. preventive maintainace was done to the pc where custom scanning was done, after then the internet is not reachable. what could be the possible reasons?

  27. how do i get rid of a lease that is obtained on my wireless network ??? it wont let me connect to xbox live if i have a lease. what is a lease and how do i stop them from coming

  28. The last couple of days I experience a weird problem, after browsing a certain amount of time my internet connection drops, most times it will restore all pages by closing and reopening IE. Although my VOIP phone plugged into the same modem works fine.

    Upon reading this article I did change the setting suggested above as to auto detecting the speed, but guess what, the connection just dropped before posting this comment! This is second attempt..

    Any ideas?

  29. My verizon network drops too. The last time it happened, the helpful technician (two other non-helful technicinas later) who got me back on said that the server could not find my IP address! It is now doing this very frequently. Time to drop verizon altogether?

  30. I use my home lan for streaming videos and suddenly had drop out problems with the video streams and failure to copy large files across network. Tried all sorts of fine tuning and then installed the Windows Update “optional” peer to peer name resolution protocol (which I think is also part of SP3) and the problem appears to have vanished. It wasn’t immediately obvious to me that I had a peer name issue to resolve but perhaps I did!

  31. If the network you are using is Ethernet but the destination computer is on a Token Ring network, can you transfer a document with using routers? I have this question in college, in which I just started. I’m trying to find the answer but I’m lost.

  32. i have two computers in the same router(4 ports) i install dvr in the first one, from the second one i try to see the cameras throw client software but i have MASSEGE LOGIN FAILED. i make ping between the computers and it is ok, i turn off the firewall but still i have the same problem login failed

  33. I’m amazed. Not only does this tip keep me connected, but it also allows me to enable my cable connection after it has been disabled. I wonder why something so simple was so hard to find?

    Thanks, Leo. Phil

  34. I tried changing the “Auto” but continued to have the problem. It may be a conflict in firewalls. I’m using Zone Alarm and didn’t realize Windows firewall was also operational. Typed Start>Run>Firewall.cpl Firewall appeared to be off. Then went to Advanced and found that my wireless was an exception. Now that is off. We’ll see what happens with zone alarm only.

  35. Tried the speed change trick on my NIC and it now shows “connected” whee before it showed “unconnected” to the internet, even though it was reading it. Thanks.

  36. Help!

    My company just went with VoIP and it is a great money saver as well as the features you get are great.. Here is the problem…

    We have a VPN with a location in Ohio and one in Minnesota. The OHIO location is working 100%, no problems and we have a Cisco 1841 Router. At the minnesota location, we have an ASA-5505. Now here is the kicker.

    In Minnesota, while we were testing with the connection coming into our modem from our ISP, we have 7MB DSL/1.5UP and the connection came in from the modem to the Edgewater Router. From there due to we were testing, it went into the WAN port on the Cisco ASA-5505, and then from there it went from the LAN port on the ASA to a 3-com Switch. All is showing at AUTO NEGOTIATE we are running at 100MB FULL everywhere. Then of course the PCs hook into the SWITCH.

    Here is the problem now… We ran this way for well over a month testing our VOIP phone they gave us, however, it was just hooked directly into the EDGE and not through a PC on the network as the setup is now. ALL WORKED GREAT! no drops in connectivity.

    NOW, here is the setup with the VOIP PHONES on the network in MN…..

    The DSL comes into the WAN on the EDGE, PORT 1 of the EDGE hooks into the CISCO ASA-5505. Port 2 of the EDGE hooks into the 3-COM SWITCH and the EDGE is DHCP ENABLED as well. The Cisco is not DHCP Enabled as we had a problem with it attacking itself with a LAND ATTACK. Anyways, so we have so far DSL to EDGE, EDGE to SWITCH and then EDGE to CISCO to SWITCH as well sorta like in a circle.

    All pcs on the network are statically assigned. All phones get DHCP settings from the EDGE. The PCs are told to go through the ASA and the phones obviously go through the EDGEWATER VOIP ROUTER. The connections on the PCs look like clockwork they BLIP for a second, long enough to get our AS.400 connection back to OHIO to drop and have to reset. THE PHONES ARE NOT AFFECTED. We have tried everything to fix this and TO ME, it looks like a TIMER is resetting the connection every 4 hours.. Our VOIP provider says the EDGE has no timers enabled for resetting anything and our CISCO has been working fine as well. This dropping only started when we hooked the EDGE to the CISCO and to the SWITCH along with the CISCO hooked to the edge and the switch as well..

    ANY HELP IN RESOLVING THIS would be GREATLY APPRECIATED. Its causing a lot of headaches due to our MN location uses CLIENT ACCESS from IBM on their PCs to connect to our AS400 in OHIO via TELNET port 23 connection TCP. THANK YOU.

    Tech Admin in Ohio

  37. I had the same issue…. except I turned the “roaming aggressivenes” setting on my wireless adapter to “low”.

    I’m back to reliable high speed now.

  38. I made the changes as above and my internet was fine for 2-3 days then it started to cut out again. Not as often but it’s still annoying. So far when I’ve restarted, it seems to be OK until the next day and we go through the process again. What’s happening? It’s driving me insane.

  39. Happened on both Linksys and NetGear rounters. Has CONTINUAL network connection loss – every few minutes, which is why I went from Linksys to NetGear. Seemed I had to replace the Linksys every couple of months.

    Anyway, after spending dozens of hours researching and seeing that this is a fairly common problem, I tried about everything. Then one day I read something about the router being too close to our furnace, water heater and incoming phone and cable lines – so I moved the router to another part of the house and, knock on wood, it has been several weeks with no network connection loss.

    Don’t waste your money with support until you have tried the above test. Just move your router away from anything the Might have radio waves involved!

    Hope this helps~~~~~

  40. For VOIP issues please make sure it is registered.
    how to register VOIP? just simply try to access the IP address of your VOIP box in the IE (it doesnt matter if you browse internet, aslong your modem is properly connected to VOIP box and the VOIP bosx is properly connected to the PC)Please note that the voip will not be access if it is not connected wired.It is better to use ethernet cable for VOIP so you will have no problems in the future. – [Name Removed]

  41. I had been having similar problems to many of those described above after moving to a wireless router. I finally think I have cracked it.

    Under Configure => Advanced there is a setting called ‘Network Type’. I had this set to ‘Infrastructure’. Since changing this to ‘802.11 Ad Hoc’ I have had no further random drop outs.

    I’m not suggesting this will be a fix for everybody but hopefully there are a few other people out there who this works for!

  42. I am part of a team who have a router connected to a switch and I experience connection dropout all the time. As our system works from a server dropout looses currents documents being worked on. What could wrong. Our it department can’t find the problem. We have 30 sites using bt routers who do not experience connection dropout.

  43. We’ve got the same problem with one Dell Vostro laptop on a small network (sbs2003 server with three desktops and one laptop connecting). Have replaced network cables, turned off auto-negotiation. Have just now tried in Offline Files Settings, Advanced “never allow my computer to go offline” -it STILL goes offline! would love to see any solution that works and will let you know if i find something that works for us

  44. if the connection drops out frequently, it is called intermittent SYNC. The best way to resolve this issue is by changing the modem modulation type to G.dmt. It will help your internet connections more stable. But not all the modems has an option to change the modulation type.

  45. Dear Sir/Madam,
    My computer is on “DIAL-UP” unfortunatley, and,for some unknown reason it keeps automatically hooking into the “internet” when I DON’T want it to.Like my Wife gets mad when she’s on the phone and it interfers with her conversation, so she tells me.SO…what can I do??? I tried changing the settings but when I do that, it wont hook into the internet,will I ring up my I.S.O. ????
    Cheers Graeme W
    ps. Looking forward to hereing from you Guys. 19/08/2011

  46. @Graeme
    Could be a few things causing that. Unplugging the modem cable when not accessing the Internet should work.

  47. first of all, i have a broadband connection and a trendnet router trendnet tw100-s4w1ca (with the latest firmware update) and my network connection drops every so often! … i’ve read this article and i’ve changed my network card speed from auto negotiation to 10mbs full duplex/half duplex; 100mbs full duplex/half duplex; 1gbs full duplex, and except 1gbs full duplex that says that my network cable is unplugged, on the other settings, my speed drops from 5-6 mB/s under 1 mB/s, of course, my network connection doesn’t drop any more! How can i fix this?

  48. I need to add that if i don’t use utorrent, may network connection doesn’t drop to often, but if i use utorrent, it drops in maximum 3 minutes after i’ve started a download!

  49. my dsl connection is very slow. in a day the @ light of my modem get for about 10 hours and the internet does not work at that time please help me

  50. Once the power went and back, My modem is automatically resetting the wifi password and it getting unlocked. I m confused that what is the exact problem and how we overcome from this…..

  51. At work my desktop is hooked to a lan line and my internet drps every 2 min and some days it is every 3 min and once a wk lol half the day no drops then it will start again every 2 min someon please help its very frustrating

    • do you have unlimited data package ?
      when does your connection drop ? i mean what were you doing at that time and how many people use your unlimited DSL?

      i think PTCL disconnect you because you are using too much bandwidth.
      Unlimited is not actually unlimited.

  52. hey guy i am also having issues with DSL, it keep on disconnecting.
    i think PTCL disconnect me for using too much bandwidth .
    because i have unlimited Data Package.
    Can you answer me are you guys also using unlimited data Package ?

  53. Hi Team,

    We have an Fortigate 100D at our office .

    We are 100 people, and I am the only one using the bandwidth.

    Every some time/minutes the firewall experiences an issue where the web pages no longer load, and everything just drops for about an minute. This started happening as of an week ago without major changes.


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