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Why Do You Regularly Reinstall Your System?

Question: I read that you regularly install your system completely from scratch, if I understood correctly. Why is that? Is that against potential malware that didn’t get detected? Do you do this monthly, or twice a year? Regularly reinstalling all the software anew should take you some hours, even if you’re fast. Or did I misunderstand something.

You understood me correctly.

While I don’t do it as often as I once did, it’s absolutely something that I need to do from time to time.

Why do I do it? In part it’s the nature of software, and in part it’s the nature of what I do.

The good news is that it has nothing to do with malware.

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Software Rot

The villain here is something called “software rot”.

The concept is very simple: over time a computer system becomes less well organized, less coherent and more chaotic. All that leads to degraded performance and instability.

In other words, your computer gets slower and less stable as a result of use over time.

The reasons for software rot vary, but in general it boils down to the applications on your computer – and to some extent Windows itself – constantly saving things, erasing things, moving things around and just generally going about their work, without completely cleaning up after themselves.

Random files might get left in place. Registry settings might be left in an incorrect state. Incomplete downloads might result in program instability or confusion. A failed update might never get re-tried, resulting in a partial update. All of this very slowly accumulates and eventually gets in the way as your computer operates normally.

And there is one particular offender that is easily the worst.

1's and 0'sTrying out software

Installing and then uninstalling assorted software will hasten software rot like nothing else.

And, as you might imagine, that’s something I do from time to time as part of my work here with Ask Leo!. I install things. I try things. And I uninstall things.

And my system slowly becomes less and less stable.

One problem is that there’s no actual agreement on what an “uninstall” should do. For example: should it uninstall only the software, leaving your settings and preferences in case you reinstall? Or should it just blow everything away completely?

Leaving components behind contributes to software rot.

Another problem is that setup programs, which are also responsible for uninstalling software, rarely get the respect, or the resources that they deserve. That means that they’re often created by less senior people, and often don’t get developed or tested as thoroughly as the actual product. The net result is that uninstalls often leave things behind. Things that contribute to software rot.

It’s getting better

I’m pleased to report that things are getting better since I wrote that comment.

In years gone by I’d expect to reinstall Windows as often as once a year, though more often I could let two years pass before getting frustrated enough to take the plunge. As you said, it’s a fair amount of effort – I set aside the better part of a day to do it.

More recently I’m not feeling the need as often. That’s due to two things:

  • I’m now more likely to use Virtual Machines for my experimentation. Much like an image backup it’s easy to save and revert a VM to a known-good state, such as before the tested software was installed.
  • Windows is getting better. There’s no doubt that more recent versions of Windows are more resilient than their predecessors. Not perfect, but definitely better.

The net result is that these days I’m more likely to reinstall for other reasons – like new hardware or OS upgrades – than I am for software rot.

Implications for the average user

As I said, I’m kind of a special case when it comes to my computer.

With Windows version 7 and 8 I think it’s completely reasonable to assume most users won’t have to reinstall due to software rot. It’s more likely that something else will come along, like a new machine or the next version of Windows, before that kind of action is required.

With earlier versions of Windows things are less clear. Once again, with average use I wouldn’t expect to need to reinstall for many years. The problem, of course, is that with both Vista and XP it’s already been many years. Reinstalls might be called for; at which point I’d recommend using that as an opportunity to upgrade to a supported operating system.

And as always, if you’re the kind of person who likes to tinker, installing and uninstalling software often, then you may find yourself at a point where a reformat/reinstall might well be the best option to return your system to the performance of its younger and more stable days. (ProTip: take an image backup immediately after you reformat and reinstall … then the next time simply restore that image rather than go through the reinstallation hassle.)

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24 comments on “Why Do You Regularly Reinstall Your System?”

  1. Leo: you said to make a system backup after installing the OS. That’s great advice, but I’d add to that make a system backup after you’ve installed the OS, gotten the updates, installed the programs and have most of the tweaks and settings for those programs the way you like them. For me installing the programs and getting the settings right for my needs take much longer than installing the OS.

    • If you do just one, I recommend immediately after installation. (Eliminates the need for installation disks.) Doing a second after all has been installed and tweaked is a great idea and I often do that myself. What I find, though, is that my install-and-tweak phase often extends over days as I also begin to use the machine. So the machine is progressively less pristine as I use it, and I’m never really sure where to draw the line that says “OK, now I’m done, everything’s installed and tweaked”.

      • Hi Leo,
        I agree that it can be difficult to know when you have finished tweaking so I do a kind of leapfrog operation. By that I mean I will take an initial image just after OS installation. This image I archive for future use. I then do the basic personalisation of the desktop and settings and install apps that I know I will pretty much always use and then make the second image. This is also archived . I will then add in all the less certain stuff and make notes on any changes I have made. When I am through tweaking I will put on Image number 2, redo any changes I wish to keep and install the apps I have decided I want and then do a third image.
        It sound like a lot of work but disk imaging is so quick and easy as is restoring an image that it is very little trouble and it is nice to know that when you are done you have a nice clean image to start from.

  2. I have found when my system is running slow and just plain acting up, it’s time to wipe the drive and reinstall everything. Sometimes that is annually, but lately I’ve been able to go almost 2 years between clean-ups. I have to wonder how many technophobes get to that same point and assume they are irreversibly infected with malware and rather than attempting anything too technically challenging, they go out and buy a new system. Could the incomplete uninstall problem be at least partially intentional on the part of OS designers? Sort of a planned obsolesce feature?

    • Hi Christian,
      Are you trying to say that you can’t be bothered to do a daily restore and full backup ?
      Shame on you.
      (not to be taken seriously)

  3. I now use an SSD for my OS boot drive and separate HD for data. This way I can reformat or repartition the drive without affecting my data. I have been using a seperate partition on the HD for many years before SSDs became affordable.

    • Hi Bob,
      I followed the same path as you but have found one drawback, I now feel obliged to perform the extra job of a secure erase on the SSD before restoring an image to it.
      And I was told that SSD’s were supposed to speed things up !

  4. Thanks for all your useful hints and comments. I use my laptop for business and out of self-defense have had to learn to perform a reasonable degree of IT work including cleaner routines to keep things going. I have done two re-installs in the last six years with the same laptop and came out okay. I now have a program called Revo Uninstall Pro. I do download trial programs from time to time and use this Revo Pro to un-install because it has a scan feature that finds all the registry traces and such and displays them so you can see what’s left behind and remove them along with the uninstalled program. I think this Revo works pretty well because a few times after I used it, I went into the registry myself searching for remnants and all traces of the uninstalled program were gone. BC

  5. When I get a new laptop, I will image the manufacturer’s installed stuff first. I make sure I have video, audio, networking and any other custom programs my new laptop needs to run well. I will create a D Partition if it is not available so I can copy needed program files there for ready install later on. Do I need a separate partition? Probably not. I just like it.

    THEN I will reformat and do a clean install. I had purchased a Window 7 Family Pack so already had what I needed to do that. And yes, you can do a clean install with an upgrade Win 7. Look online for the instructions to do that if that is what you wish to do. I had an iso of Win 7 with SP 1 on the hard drive that I was able to use so that made MS updates easier later on.

    After installing Windows itself and all necessary drivers, I will again image. Usually I will then do the MS stuff that gets more and more time consuming as I get away from its initial phase. Then another image.

    Now, I will install things like Thunderbird, MSE, MS Office, Libre Office (Office alternative) and other programs I use regularly.
    It can take quite a bit of time for the whole process.

    My laptop has slowed down quite a bit in the past several months. Have been thinking about restoring an earlier image to clean it up. Not yet, though.

  6. There seems to be several paths to uninstalling applications. In Win 7, you can use the old Control Panel route, while some applications offer you an Uninstall option from their startup menu. Having used both of these paths, I often found empty or near-empty folders with some remnants of the target application, and these traces need to be deleted manually. I currently use Advanced Systemcare Pro (not touting it, just an example), and I find that it finds and deletes these vestigial remnants a lot better than the first two methods. Leo, could you comment on these three Uninstall methods and give us your thoughts?

    • If there’s a start menu item to uninstall it should be equivalent to the control panel path. Those run the “official” uninstaller for whatever it is you’re getting rid of, and yes, they often leave things behind.

      Tools such as you mention (I use Revo, myself) take an extra step to clear out the things that it can infer or assume are related to the application being uninstalled that would otherwise be left over. I don’t use them regularly, only when there’s a problem. My assumption is that the official uninstaller leaves things for a reason, and I’m reluctant to second guess it, unless I have some other more important reason.

  7. Frankly I am shocked that Leo does this. As a computer professional, there is nothing software related that cannot be resolved without such a drastic measure. The only times I have started over from scratch is when I move to a new computer (or new motherboard), and since I build them myself, that only occurs once every 6 or more years. Yes, I am still on WinXP on my main machine and despite all the software installations and removals, she is running as fast as ever. My next move will be in 2017 unless the mobo goes belly up before then.

    • You will spend at least as much time resolving many problems that crop up with windows by working on fixing your original install rather than reformatting. And after you spend all that time it will still never perform as well as a fresh install of Windows 7. Also Windows XP is vastly inferior in security compared to Windows 7 or 8. These newer versions will also stay running well for a much longer time. You can also very quickly change some system settings so that 7 will run really well on some really old hardware. What you’re doing is commonly referred to as trying to polish a horse you know what.

      If we had two identical computers that each had a not so easy to solve problem, caused from someone doing something dumb, or just a mystery problem and we were to race to see who could make their computer run absolutely perfect. I could have the files backed up while I go and do something else, eat a sandwich, mow the yard etc. Then come back and pop in a flash drive with windows 7, wipe it in about 15 minutes and plug the external drive back in and restore the files. You would still be messing around with that old Windows rot. And after it was all said and done, mine would still run better and snappier. When your performance degrades slowly over time you don’t even realize how much slower it has become. There is nothing unprofessional about reformatting. What you’re talking about is comparable to straightening and applying a bunch of bondo to a crunched in fender and hood, as opposed to removing them and replacing them. Sure you can fix them but why would you? They will never be as good and it will take longer.

      • @actionjksn: I respectfully disagree, and I do not think reformatting is unprofessional, just surprisiing that a pro would do it routinely to their own PC. My first defense is full and daily incremental image backups, so if something goes awry, I can copy any new or changed files of the day and run a restore from this morning’s or yesterday’s backup and voilá, it is fixed. But rarely do I even have to do that. I know my system and I know myself enough to know what I did to cause the problem, and I am able in most cases to undo it successfully. As a professional, be assured that I have a very unique configuration that would be a MAJOR hassle to rebuild from scratch. That being said, when it comes to someone else’s computer, and if the’re not able to articulate to me what went wrong, sometimes the best way is to start from scratch, but never on my own machines. In many cases I have been able to make a client’s computer better than new after a common malware infestation without formatting. The reason it is better than new is because they had unnecessary programs running at startup that I disable as part of the “tune up”. If the malware has corrupted their system beyond repair, then a format/re-install is in order. I don’t think that your comparison of auto body repair to software repair is valid because one is physical and the other is intangible (software). Hardware repair is a different story altogether and would be a valid comparison to auto body repair.

  8. I’d like to add my recommendation of Revo Uninstaller (though I use the free version). Revo by default first runs the “official” uninstaller for the application or program. If it can’t find the uninstaller, it proceeds to try to remove it by other means. Since this has never happened in my experience, I’m not sure what those other means are. In any case, it appears to do very thorough scans – post uninstall – finding leftover files and registry keys associated with the defunct program. When I want to uninstall, I want it GONE, and Revo seems to do this just fine. If it eliminates something I need (again, never happened), I know I can get it back easily in one way or another – by reinstalling, if needed.

    I do a fair amont of tinkering with new software myself, just for amusement, and I use a LOT of different apps. Customization after a reintsall usually takes me the better part of two days. My computer seems to perform to spec over its lifetime, so reinstall is always a last resort for me. I’m now also now using Crash Plan for frequent system images and comprehensive file backup. That makes reaction to sudden degredation or problems a breeze. Progressive deteriorization does not seem to be a problem for me.

  9. For uninstalling programs you cant beat Revo. I have used it for years. Never had a problem with it.
    But for some reason some apps dont show up in Revo -nor in the Control Panel for that matter. For those apps I use a program simply called Uninstaller, by Puran Software. This is a great program because with it you can browse to anywhere in your computer and force an uninstall of any app. Its great for uninstalling the apps that Revo cant.

  10. One reason left off which has really helped any system that becomes slower over time due to more and more startup items (doesn’t help reliability issues though) is using a SSD as the system drive, even for old SATA I systems, the speed pickup is very noticeable (not quite amazing) and quite comparable to a late model system on a non-multitasking basis; multiple cores will still kick butt on that account.

    On the other side of the equation, one of the heaviest contributor to software rot in particular is security programs. They tend to need to get more deeply integrated with a system to “protect” it and as such, cause much more detrimental effects when something goes a bit wonky.

  11. I, too, have successfully used Revo (free) for many years. I reboot (to insure registry hooks are cleared) then chase down any more leftovers with AgentRansack (free)… simply deleting found trace files/folders.

    I follow up with a complety configured cCleaner incl the little known and oft overlooked Registry cleaner option (2nd down on left) and never fail to invoke an old non-crapware-loaded early version of Glary Utilities. Be careful with Glary because the author’s site now will totally spam you when you download the current version loaded with piles of junk. My version must be 6 or 7 yrs old.

    In my 10-year-old pc virus removal business I rely heavily on for daily updated versions of AdwCleaner, rKill, ComboFix, JRT (junkware removal tool), & tdssKiller rootkit removal tool. Can’t say enough about the HUNDREDS of helpful tools and apps found there. Between Leo’s many years of truly unbiased and solidly dependable help and Bleeping Computer’s fantastic library & blog/s I would not want to be in this business.

  12. I really hated going to Win8 and now Win8.1 but thru the gift of ClassicShell site I am very well broken in with the
    familiar format that it provides similar to XP.
    There’s an old saying, “if it ain’t broke,don’t fix it!” and that holds well on what all the above conversations have been
    about. I’m pretty conscious about keeping garbage off my desktop. I do a fair amount of downloading ‘stuff’ from the
    web and what I do is “ALWAYS” download to my desktop, scan with Avast (my preference) and Malwarebytes and 99% of the time if something big is attached it’ll be caught. With that being said, there’s the 1 % left of crap that gets hung up
    as adware or traffic monitoring and typically all these are less than 5MB in size. A lot don’t do ‘great’ harm but if it builds up on a lot of downloads they will slow your system down and that’s when the ‘rot’ causes you problems.
    If I could find a “REALLY USER FRIENDLY” program for backing up my system I would use it but even the freeware stuff
    comes off not really that user friendly. Typically there are too many tables that you have to assume direction on so I
    don’t have something yet. I defrag my HD at least once a month, scan with Avast, Malwarebytes, and Superantispyware and so far ‘all seems to be ok and system is fast’ and dependable….so far.

  13. Coming to you live from a Dell Optiplex GX270 P4, Single Core, with a 12 year old installation of XP Pro,
    it started as SP1a, updated to SP2, then finally SP3
    still using the OEM installed 120GB Seagate HDD

    and it was configured correctly from the beginning,
    – no user history
    – no web history
    – no download history
    – no user tracking
    – no recent programs list
    – no recent documents list
    so far the user portion of the registry NTUser.dat is only 12.5MB

    disable all the “helpful” spying and windows doesn’t slow down
    it takes an exponentially longer time to notice any “slow down” of any sort
    it still gets 30 – 35 second boot time

    oh, and I have 3x 18 year old win 3.10 / DOS 6.20 installations that never slow down either
    There must be something about storing history in 9x & NT that causes bloat and rot ?

  14. If you have a low-spec PC like me you can’t run virtual machines to try new apps safely.
    Then why not backup Windows with Macrium before install and if you don’t want to keep the new app/program don’t uninstall it, restore Windows instead.

  15. Hello unfortunately it happen to me to but my laptop is crash I don’t know what they did to it I tried to reset it but it doesn’t work. What can I do to fix it.
    Thank you

  16. I was uninstalling cause it was getting so slow. And them mouse stopped
    Working to a point can’t use it. So today we got a new pc. I’m trying to fix this one. Download window s from Microsoft then we will see if we can just that pc for browsering or have to buy a key. It come with a key .


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