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This folder is taking up nearly a GB of my C partition. Is it possible to just delete it?

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8 Answers 8

up vote 31 down vote accepted

I think it should be safe to remove the files, provided you're able to download them again in future if they're needed or if you have access to your original install disks. I had something similar on my computer, I just deleted it and install things from the original disk every time it asks me now. Inconvenient, yeah; but I don't often install stuff and it's a lot better than having a whole ton of space on my hard drive wasted.

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Yeah, C:\WINDOWS\Installer\$PatchCache$ on my hard drive is empty, so I guess if it's safe for me it should be safe enough for you. –  Sticky Dec 13 '09 at 7:42
I'll try to move it and see what happens –  James Dec 13 '09 at 8:21
Reading the command line options for msizap, I wonder if manually deleting these files is indeed safe. Like for msizap * Microsoft writes: Removes all Windows Installer folders and registry keys, adjusts shared DLL counts, and stops Windows Installer service. Also removes the In-Progress key and rollback information. Does Windows also do this when manually deleting the files? (Do not run msizap without understanding what it does; see comments at Joshua's answer.) –  Arjan Dec 2 '10 at 8:26

Heath Stewart's The Patch Cache and Freeing Space on MSDN blogs explains in detail. An excerpt:

[..] cause the Windows Installer service to cache any of the original files being replaced into the baseline cache. [..] It is this baseline cache that consumes a lot of drive space on the system drive after installing [..] The baseline cache facilitates patch uninstall by storing the original files so that they can be copied back to the target locations.

[..] by removing the baseline cache for a product, future repair, patch install, and patch uninstall scenarios may require your original installation media. If you have the drive space it is recommended that you keep the baseline caches available.

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Note that he mentions that you should only remove some sub-folders from $PatchCache$\Managed\ . For me I removed MS Office folders as they were taking a lot of space and I have DVD for them. You should be able to easily recognize MS Office folders as they have files with MS Office icon in there. –  Nux Jan 13 at 15:35

You could also try the MSIZAP utility from Microsoft. It has a "safe" option, 'G'.

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Nice. But according to the article mentioned by Scandalon: Take care when using msizap, though. "G!" is safe, but exploring other switches without understanding their ramifications could mean you cannot patch products anymore because product registration is missing (essentially making it appear to Windows Installer that your product is not there). Treat this like editing the registry. –  Arjan Dec 2 '10 at 8:19
I tried running this on Win7 (my folder's 9.2GB) and saw no reduction in disk usage. Is msizap still needed with Win7? –  Drew Noakes Apr 17 '12 at 23:48
@DrewNoakes if you used the "safe" option, then I am going to guess that those files were all considered necessary. –  Joshua Drake Apr 18 '12 at 13:57
"MSIZAP and MSICUU2 are no longer supported because they have been found to cause problems. Please use the Program Install and Uninstall troubleshooter available here: support.microsoft.com/kb/2438651"; -- 11/22/2011, Jeff Ingalls MSFT –  matt wilkie Nov 2 '12 at 17:33
@mattwilkie You may want to include that as an answer too. –  Joshua Drake Nov 2 '12 at 18:27

What I do for this folder is revisit it every now and then and only delete packages in there that are at least six months old. This way, if there's a bad patch that I need to roll back, I can usually still do it.

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That seems like a good compromise. Thanks for this suggestion! –  Jeremy Stein Aug 1 '12 at 13:41

Is it possible? Yes. Should you? Probably not, if you don't have to. Windows Installer keeps those files around because it think they're needed if you ever have to install another patch on top of them (or uninstall those particular patches).

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The solution is to use the command from Start → Run → cmd:

rmdir /q /s "C:\WINDOWS\Installer\$PatchCache$" 

Warning: This will not affect the Installer folder. All content msi files created there will remain until the program is uninstalled. $PatchCache$ can grow up to GB of size which takes a lot of my hard disk space.

This command will delete $PatchCache$, and after you finish, run

dir C:\WINDOWS\Installer\$PatchCache$

… to see if the folder is still there.

You can also use

del /q /s %tmp%

which deletes all files in the temporary folder, which are created by installing software.

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I assume the user knows how to delete the files in a folder. The question is whether it's safe to do so. –  D Coetzee Apr 22 '12 at 7:24

This links may also help.




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providing links are helpfull could you summarize it as answer and quote it as reference? –  BlueBerry - vignesh4303 Oct 4 '13 at 7:33
Welcome to Superuser. Please don't provide link-only answers as the links may die in time and your answer will become useless to future visitors. Where possible, provide the contents of the link or an abridged, helpful version of it. –  Tog Oct 4 '13 at 7:44

If in doubt, you can always go safer way: simply compress entire Installer map! Right click on the Installer map (or just $PatchCache$ map) and choose Properties. On General tab, click Advanced button. Finally, check Compress folders to save disk space. If asked, choose an option to compress all subfolders and files.

This way you can gain up to 30% of free space (or in your case, nearly 300MB), and you keep everything in case you'll need this stuff later on. And system speed and response wont be affected much since system rarely accesses this map.

You can apply this tactic to several other non-essential system maps, thus recovering lots of free space on your drive!

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