Why would anybody ever want to clean out this hidden directory? Simple, it gets full of junk that you don’t need or want any more.
Anytime an MS update fails to install or gets interrupted, regardless of the product, pieces get left in \windows\installer so that you loose disc space. This appears to be by design as MS has now removed the download for MsiZap.
If you ever wish to see how much space you can reclaim from all those uncessary installation files leftover to rot in your windows folder, download MsiZap.exe. I have chosen to link it right here for all to download as needed. This tool is a must and why on earth MS chose to remove it I will never know.
So now that you have this important file here is how to use it.
Press Start=>run and type cmd. If you are using the new crappy windows, don’t use this program cuz you know your version of windows is just too cool to need anything like this.
Navigate on the command prompt to where the file is located. I place the file in \%systemroot%\msizap.exe so that it was all ready to in my path.
Now that you have the location down just type:
Watch as lots of stuff scrolls by on your screen, or not depending on how long windows has been installed. Then go check your system drive and see how much space you have saved yourself.
This program has been able to save me and several family members lots of space. Normally its about 2-10 GBs but this one time while camping it was over 60GBs
Hope this program helps you as much as it helped me.
If you want more information and an actual reference guide please see below: