Technology in terms you understand. Sign up for the Confident Computing newsletter for weekly solutions to make your life easier. Click here and get The Ask Leo! Guide to Staying Safe on the Internet — FREE Edition as my thank you for subscribing!

Can I install programs on an external drive?

Windows XP-Home is installed on my C drive. Will programs, games and so on
run if installed on my external E: drive or do they have to be on the same
drive as Windows?

The short answer is yes, but there are, as always a few caveats and
clarifications I need to make.

Become a Patron of Ask Leo! and go ad-free!

If when you set it up a program allows you to choose a destination drive to
install onto, it shouldn’t matter if that drive is C:, your Windows drive, or
some other hard drive internal or external. For the most part they’re all just
drives, and the fact that the setup program gives you the option means there
shouldn’t be an issue.

For the record, if the setup program doesn’t give you a choice then it may
be an issue and I’d avoid trying to circumvent it.

Now, many external drives are removable. USB drives, for example, can be
removed from your computer either while it’s not running, or after clicking a
“safely remove hardware” for the device. In the later case, if a program on
your removable drive is running, “safely remove” may fail. All files on the
external drive must not be in use, and a program running from the drive is
definitely “in use”. You’ll need to make sure that all programs installed on
the external drive are shut down before attempting to remove the drive.

Now, that sounds simple enough but more complex packages often install
software that runs automatically when you start your machine, either in the
form of explicit start-up menu items, or as system services. You may
not think you’re running any software that’s installed on that external drive,
but in reality it may have installed something that is. You’ll need to figure
out what that is, and take steps to disable it, or shut it down before you
remove the drive.

“You’ll need to make sure that all programs installed on
the external drive are shut down before attempting to remove the drive.”

Along those same lines, if the drive is not installed when you boot your
system, you may get error messages on start up if a prior installation of
software onto that drive also added startup items. Without the drive installed,
those startup items may not be found, and errors may result. Menu items and
shortcuts relating to the software installed on the external drive may also
revert to Windows defaults until some time after the drive is reinstalled.

Finally, don’t expect application portability by installing it to an
external drive. By that I mean that installing an application to an external
drive, and then taking that drive to a different computer and expecting the
application to work on that machine. This may work for simpler applications,
but setting up a complex application is as much about setting up the Windows
registry as it is about just placing files. The registry will have only been
set up on the first machine. Theoretically it might be possible to set
up the software on machine A, then set it up again on machine B if the
drive letters are identical
, but I’d expect that to be highly error prone.
It’s also quite possibly against many applications licenses or terms of use
since you’re technically installing it on two machines.

So there are a number of issues related to removable media, but if you’re
just installing your software to a second hard drive, and it just happens to be
an external drive, I wouldn’t expect that scenario to be an issue for you.

Subscribe to Confident Computing! Tech problem solving & safety tips & a weekly confidence boost in your inbox every week.

I'll see you there!

10 Reasons Your Computer is Slow

Slow Computer?

Speed up with my special report: 10 Reasons Your Computer is Slow, now updated for Windows 10.

NOW: name your own price! You decide how much to pay -- and yes, that means you can get this report completely free if you so choose. Get your copy now!

26 comments on “Can I install programs on an external drive?”

  1. Excellent advice, Leo.

    Some aapplications have been designed to run external drives, such as the MS Word compatible processor, “ABIword Portable,” the Thunderbird Browser, and many Open Office applications.

    Carrying these portable applications on an external drive or jump drive can be helpful if you’re a student or you use various computers.

    Reply
  2. There is a program call MojoPac that allows one to install software on a USB drive, iPod or portable hard drive because it vitualizes the Registry. You can run MS Office and other programs like Adobe Creative Suite, and move the drive from computer to computer and use the installed applications. Very cool . Find out more here: http://www.mojopac.com

    Reply
  3. would like to know if it is possile to install an antivirus on my external drive, and where can i get the software?which kind of software can i use?

    Reply
  4. How to protect my data on my portable hard drive, from infections, while connecting to other people’s pc ?
    Thanks for any info.

    Reply
  5. —–BEGIN PGP SIGNED MESSAGE—–
    Hash: SHA1

    If your hard drive (or USB thumb drive) has a physical
    “read-only” switch to prevent writing to the device, use
    that. Unfortunately, not many do these days for some reason.

    – From a purely pragmatic point of view the answer is that you
    really can’t … at least not with 100% certainty. The best
    steps to take include:

    * ONLY connect to PCs you absolutely trust

    * turn off “auto play” on your own computer

    * virus scan the drive immediately on connecting it back to
    your own computer.

    Leo

    —–BEGIN PGP SIGNATURE—–
    Version: GnuPG v1.4.7 (MingW32)

    iD8DBQFIhLdgCMEe9B/8oqERAnoOAKCPxbL3qFBXQy8xiTqXPSALRmQthACeNpkg
    cbSbL4Y1AyYLVtzWFiQDdqw=
    =CM8h
    —–END PGP SIGNATURE—–

    Reply
  6. I am tired of formatting my hard drive and installing all the service pack files and bunch of application each time my computer hit by a virus.

    1) From the above comments it is clear that we can install Application on separate drive internal or external as long as the apps get installed on that separate drive.
    Is it possible to create partitions of my current internal hard drive C i.e. install operating system on C and install all the apps on the partition drive and if I have to format my C drive will the apps still work with that operating system when it gets reinstalled on C drive.

    2) How to make a complete copy of C drive that includes boot and license files and all the apps to put it on DVD or multiple DVD’s so in case of formatting hard drive I can just put the DVD and install everything.

    Any comments will be greatly appreciated.

    Thanks

    Syed

    Installing on an external drive doesn’t somehow prevent viruses from attacking what’s installed out there – they’re just as vulnerable. Taking a full backup image once you’ve set up a clean machine is one way to have something you can restore to so as to avoid having to reinstall all the time.

    But if you’re constantly getting re-infected, that simply shouldn’t be, and I’d re-evaluate your security software and/or your safety habits.

    – Leo
    09-Jan-2009
    Reply
  7. I currently have a desktop PC and laptop setup on my wireless network. I have recenly added an external hard drive, which I have also made available to both computers on the network.

    I am curious to know, if I install applications onto the external hard drive can both netwroked computers run that application?

    Thank you!

    Typically, no. Installation also sets up information on the machine you’re installing it on, most notably in the registry, which won’t be set up for those other machine. A few apps can work as you describe, but almost all that use a setup program do not.

    – Leo
    18-May-2009
    Reply
  8. REALLY need help with this one
    When I download games, I am able to choose to Install to my external hard driev (g drive)
    However, when I open the file, it starts to Install the game by extracting files to my normal hard drive..
    I ran out of space on my internal (c drive) and the installation was cancelled.
    How can I get files to extra to my external drive, or not extract at all?

    -please help its really frustrating

    Reply
  9. copied a program folder to an external drive as a backup and realized after a while that the program is booting from the external hard drive now… how do I correct this?

    Reply
  10. I have two drives; (:C)and (:D) and it’s a partition. I tried to install Microsoft Office in drive (:C) because it is more spaceous than drive (:D). Unfortunately, when I did install, why does it takes drive (:D)’s space too?

    Reply
  11. I recently purchased an external hard drive (1TB) and i was wondering if there is any way i could make a new user on my computer and only use it for playing games. If i installed the games on to my external hard drive would i still get errors when i start up my computer even although no other programs are installed on that user.
    Sorry if thats hard to understand.
    Basically can i make a new user on my computer that is totally hard drive based (apart from operating system of course.

    Reply
  12. Hello. I a few months ago bought a Microsoft Freelancer PC game from amazon with cd, brand new. Is it possible to portablize this game? Thanks!

    Reply
  13. I have a problem. I use Steam for my games. (It is an internet system to download and file games. I plugged in my external hard drive to my computer, and the space on it jumped from 300gb to 14000gb. I installed a game, but when I tried to run it, it told me that it was missing maps. How can I fix this? It dosn’t give me a file location to put it or anything.

    Reply
  14. I installed adobe master collection CS4 on a hard drive and then the hard drive broke and i got a new one and now i cant install adobe master collection CS4 again.

    Adobe’s copy protection scheme can be somewhat painful at times. You should be able to contact Adobe customer support for assistance, though.

    Leo
    23-Aug-2010

    Reply
  15. I want to install wordpress on my external hard drive. Can I do this and how? Thank you.

    WordPress is something you install on a web server, not typically on your PC at all.

    Leo
    21-Dec-2010

    Reply
  16. I am reformatting an older pc with the orignal windows xp. c drive it very little ram ( runs slower now with all the updates). I have an internal hardrive with 2 gig…can I install xp on here and pc will run? also, do I have to have all the service packs installed? Plus, I looked up all the drivers to update and there are 78. Not sure which ones I really need as they all say “optional” on them. (dell pc 4300)

    Thank you!

    Reply
  17. Hi There Leo – Thanks for the help. Okay there is this product “USB 2.0 to IDE/SATA Cable with Power Adapter -here’s the link: – http://www.ultraproducts.com/applications/SearchTools/item-details.asp?EdpNo=3276554&Sku=ULT40112
    Question is can programs be run with this from external old xp hard drive connected with usb to new machine with new windows 7 professional? This could be so fantastic for so many if possible.

    It depends on the program. If the program would work under Windows 7 without needint to have its setup program run, then sure, it’ll run no matter what drive it’s on. How the drive is connected or what OS the drive used to be used for does not change the fact that you’re running the program under Windows 7, and doesn’t aleviate the need for a setup program to be run for many applications.

    Leo
    20-Jan-2011

    Reply
  18. Does it work for online gaming programs? Since it doesn’t have limitations on how many hardwares I can install it on, and logging in process comes up after the program starts running..? If specific game type is required to know, it’s mmorpg.

    Reply
  19. Actually Ive installed several games on my external and they run fine from different computers i hook it up to. Relatively new games like Cod4 – Modern Warfare for instance.

    Reply
  20. all of my program files are installed on alternate drives. just in case my windows wants to crap on itself. which it did after 3 years and 2million files (literally) later. Upon angering myself, I tried something odd, I did a tiny lil fresh install on a junk HDD, and added my other windows library’s, directory’s to it, and BAM! everything worked again. I BS you not. RAGE3D, Crysis1,warhead,and 2. Rfactor, Abelton live,, Reason, AVA. All of the programs that I was dreading to re install worked. Some random programs would say cant find yadda file, but if that was the case, just use the original .exe on that drive to launch it. *just make a short cut to it and move it to where you like. 😀

    Reply
  21. Do you think I dare chance it? I want to put my e mail programme on my external HD for the very reasons that LaTrice said. My awful HP desktop after 4 or 5 new motherboards and the HD finally was even corrupted and I lost all my years of EVERYTHING! I love Incredimail (I know many people don’t) anyway. I really want to try to put it on my external drive, note it does NOT give you the choice of what drive you want to install it on. And it puts it’s files for folders places I can not find anymore. That would be the main thing the folders files that take up so much of my HD space. But the whole programme needs to be on my external drive. Do you recommend putting all my WINDOWS files from C:/WINDOWS onto the external drive? Is that what it needs? Now does that mean COPYing them or transferring them? I don’t think my C:/ drive will operate without having them on it will it? So who ever posted they put the WINDOWS directory on their ext. HD and all the programs worked was not totally clear. I DO want to give it a try. I have my emails all over 4 different programmes and can’t find a thing. Thank you very much for your time in considering this request. Antoinette

    Reply
  22. @Antionette
    That sounds very scary! External drives can also break, so even if you go to all the trouble to do that… you are still risking everything. Seems like you’d do better to try to find the source of the computer problems (poor ventilation, dust, dirt, electric surges?), and also do regular backups. No matter which drive goes out you won’t lose everything if you do not have it in one place.

    You should start by watching Leo’s backup webinars. That will give you a good foundation in backups, and an idea of how to move forward:

    Backup Webinar

    Reply
  23. Antoinette,
    did you try installing and running Incredimail on an external hard drive?

    I save my Incredimail data (mails etc.) to ext hard drive, but since I travel alot, I would like to have the Incredimail program itself on the ext hard drive too – to have exactly the same view on my PC and laptop.
    Is there someone out there who has tried?

    Reply

Leave a reply:

Before commenting please:

  • Read the article.
  • Comment on the article.
  • No personal information.
  • No spam.

Comments violating those rules will be removed. Comments that don't add value will be removed, including off-topic or content-free comments, or comments that look even a little bit like spam. All comments containing links and certain keywords will be moderated before publication.

I want comments to be valuable for everyone, including those who come later and take the time to read.