How do you clean up the windows/installer folder on a xp machine. I looked on different forums, but the tool many mention is no longer officially supported and from what I understand not specifically for this task. Also, I was confused on which tool to use or how to use it. The reason I ask this is I have an older computer with ~86gb drive and ~80gb of is being used by the windows/installer. I'm assuming that at least some of these are glitches and shouldn't be in there.

Note that the person who uses the computer mentioned trying to interrupt an install at some point and I don't know if this has anything to do with it. Also, there are not that many programs installed on this computer ~25.

Also, I know that similar questions has been asked several times already, but the accepted answer Is it safe to delete from C:\Windows\Installer? is mainly talking about is it safe to delete (along with most of the duplicates). I'm asking how to find and delete the files that shouldn't be there especially since were not talking 5-10gb but something that practically fills the entire hard drive, and for those who are wondering I ran CCleaner, but it doesn't seem to check this folder.

  • I'm asking how to find and delete the files that shouldn't be there Define “shouldn’t be there”.
    – Synetech
    Dec 15, 2012 at 6:37
  • @Synetech I'm assuming there are either orphaned, duplicate, or perhaps corrupted files.
    – qw3n
    Dec 15, 2012 at 14:35
  • What is likely to have happened is that one of the programs that was installed had a poorly written installer which kept failing and each time, it would create a new folder instead of generating a GUID and using that for each install attempt. As such, it is likely that most of the offending folders will contain mostly the same set of files. Of course there’s no way for us to know for sure, so you’ll have to actually take a look in them to find out what’s going on.
    – Synetech
    Dec 15, 2012 at 21:33

2 Answers 2


Your best bet is to use the Microsoft Installer Cleanup Utility (msicuu). It is a front-end to msizap which can let you safely (more or less) completely (more or less) remove Windows Installer programs and all of their files and registry entries. Of course you would then have to reinstall any programs that you did want (e.g., if some program’s installer is defective and kept failing and creating new folders instead of using the same one).

If you don’t know which items to nuke, use a program like WinDirStat or SequoiaView to find out which files/folders in the Installer folder are excessively large. Then you can check the Summary tab of the Properties dialog for the .msi files to find out the product name:

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I'd start with Disk Cleanup.

Then, try this: http://support.microsoft.com/mats/Program_Install_and_Uninstall/ to possibly clean up the old files. It's the replacement for msizap.exe, which might be what you were thinking of before.

  • The Disk Cleanup wizard is not related to this, but the Fix-It may indeed help (it’s actually more of a replacement for MSICUU than MSIZAP; at least according to their docs).
    – Synetech
    Dec 15, 2012 at 21:30

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