The Windows (10) Installer directory is massive, over 25Gb for me.

Is there anything that can be tidied up here?

Also, what's it for?

Follow up

As removing it seems like a bad thing can I store it somewhere else? It definitely doesn't need to be on the SSD.


Can you safely delete files in the %windir%Installer directory?

Along the same lines as removing items from the Windows component store to save space, we have recently seen a couple of questions come in about the Windows\Installer directory. This is a hidden system directory; it is used by the Windows Installer service to cache installer data files for various applications. Over time, this directory will grow and can eventually take up an amount of space that might cause pressure on thinly provisioned storage, such as virtual hard disks.

So, the question usually asked is: Can I safely remove the files in this directory? The answer is flatly: No

First, it is not supported. If you remove files from this directory and have >issues, you may need to reinstall the application to get back to a good state. Therefore, that would suck for both you and the engineer that needs to deliver >that message.

Second is the overall idea that you really should not remove items in the Windows directory. We build and test our software based on the existence of specific files and directories. When those files and directories dont exist, bad things can and will happen.

The proper way to alleviate space pressure in this directory is to uninstall any unneeded applications.

Can you safely delete files in the %windir%Installer directory?

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