Windows Installers directory size

Problem

The problem is very likely to be known to people who bought small SSDs for their system partition. Just like me.

After around 2 years, my C:\Windows folder was huge, taking up over 60% of my C drive (~60GB), due to the C:\Windows\Installers folder (30GB). As you can imagine, that might hurt when you simply don’t have anything you could remove and you need some free space to install something on your computer.

I have faced this problem on a machine with Windows 7, but the solutions will apply also to the newer versions.

What is this crap?

You may find a lot of content on the internet that will convince you to not delete this folder as it is crucial for keeping the installations made on your computer working fine. Like on this MS Guy blog:

C:\windows\Installer is not a temporary folder and files in it should not be deleted. If you do it on machines on which you have SQL Server installed you may have to rebuild the operating system and reinstall SQL Server.

The Windows Installer Cache, located in c:\windows\installer folder, is used to store important files for applications installed using the Windows Installer technology including SQL Server and should not be deleted.

Okay, so you say that windows should be eating 60GB and it’s fine?
Looks like it.

Solutions

PathCleaner

I’ve found a nice cleanup tool called PatchCleaner.
The application is quite easy in what is it doing, according to the author:

The windows operating system holds a list of current installers and patches, that can be accessed via WMI calls, (Windows Management Instrumentation ).

PatchCleaner obtains this list of the known msi/msp files and compares that against all the msi/msp files that are found in the “c:\Windows\Installer” directory. Anything that is in the folder but not on the windows provided list is considered an orphaned file and is tagged to be moved or deleted.

It has a very simple interface:

PatchCleaner

When you run it, it looks for orphaned files from the Installers directory and allows you to either delete, or move them to another location.

I recommend to move the files first to another drive and then check if you won’t experience any problems. If no, then the folder may be deleted in the future.

It saved me around 20GB of space, totally for free!

Compression

This one is easy, but it’s really worth trying, just right-click on the directory -> properties -> advanced -> tick the compress content checkbox -> also for subdirectories.

Since we don’t use these files on a regular basis, it’s a good idea to compress the content to save up some space. There are actually more places worth looking, just by sorting the windows subdirectories by size:

Windows

Directory link/junction

Another solution that has been proposed is to cheat windows by moving the directories to another path and create either symbolic link, or junction for the directory. You can read more about this approach in this superuser topic:

I will quote the junction solution so that you don’t need to browse it back and forth:

Start a command prompt as administrator.
Take ownership of installer directory and all its files:

takeown /f "C:\Windows\Installer"
takeown /f "C:\Windows\Installer\*"

Move C:\Windows\Installer to a new spacious drive, let’s say E:. For convenience, it’s better to create a subfolder to gather all the future junctions in one place, e.g. E:\Win7-Junctions, so the new path will be E:\Win7-Junctions\Installer. Cut-paste from Windows Explorer should be enough to move the installer folder.

Make sure that C:\Windows\Installer is really gone and that all files have been moved to E:\Win7-Junctions\Installer.

Create the junction:

mklink /j "C:\Windows\Installer" "E:\Win7-Junctions\Installer"

The syntax is:

mklink /j [destination] 

Verify that the junction works by creating a small text file in E:\Win7-Junctions\Installer and seeing it materializing in C:\Windows\Installer as well.

Done. Check within “Add or remove programs” that installers are still working (Office is a good candidate to start with).

Conclusions

That’s insane Microsoft forces users to proceed such way, but since it’s only a software, for each solution there are usually at least few solution.

In my case, after cleaning with PatchCleaner and compression I gained over 20GB of space, which saved my windows installation (at least) for months. Hope it will save some more GB of yours!

Stay tuned.

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