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.