Can I delete the folder "C:\WINDOWS\Installer\$PatchCache$"?

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.

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

"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!"

"You can delete the folder content.

Follow these steps:

1) Stop Windows Installer the service.

2) Set the registry key that indicates the maximum folder size to zero.

3) Delete folder content.

4) Start Windows Installer the service.

5) Stop Windows Installer the service.

6) Set the registry key that indicates the maximum folder size to 10 (default).

7) Start Windows Installer the service.

Example:

Net Stop msiserver /Y

Reg Add HKLM\Software\Policies\Microsoft\Windows\Installer /v MaxPatchCacheSize /t REG_DWORD /d 0 /f

RmDir /q /s %WINDIR%\Installer\$PatchCache$

Net Start msiserver /Y

Net Stop msiserver /Y

Reg Add HKLM\Software\Policies\Microsoft\Windows\Installer /v MaxPatchCacheSize /t REG_DWORD /d 10 /f

Net Start msiserver /Y

Extracted from:

http://www.sysadmit.com/2016/02/GPO-Reducir-tamano-C-Windows-Installer.html"

"Instead use MKLINK to junction the folder to an alternate drive if you have space

• on drive D: create sub folder named C

• cut and paste folder Installer to subfolder C-Windows located on drive D:

• run CMD

• type: CD C:\Windows

• type: MKLINK /J Installer D:\C-Windows\Installer

• type: EXIT"