About the "C:\Windows\Installer\" folder

My question is regarding this "C:\Windows\Installer" hidden systems folder on my Windows 7. I am sure it is present on Vista and maybe winxp too. This folder appears to contain .msi and .msp installers for the various software on my computer including windows patches. It is taking up significant real estate on my system. It is currently 1.63 GB and growing. I did a fresh format 4 months ago so in 4 months it has grown from about a few MB to 1.63 GB!

Is this folder important? What is its purpose?

Are the installers for backup purposes only? Can I safely delete them?

I am sure most of you like me do not want unnecessary junk on your system and this folder appears to contain only installers for the software on your computer.

p.s. the installer files inside the folder are renamed. You will have to right click, go to properties and then details to see which software the installer belong to.

 

Don't take my word for it but I'm fairly certain you can remove them.

Get a second opinion first.

 

That is what I thought but I wanted some expert advice first as recently I had deleted msocache folder on my system and could not apply MS Office 2010 SP1 without it.

 

Have a look at these:

http://superuser.com/questions/197148/i-deleted-windows-installer-folder-is-there-a-chance-to-repair

http://www.cypherhackz.net/archives/2009/04/19/delete-files-in-cwindowsinstaller/

Don't delete any folders. As for the installer files themselves, I'd be very selective and cautious about my choices.

 

There is a lot of confusing info out on the web about the purpose of this folder. What are these installation files here for? So one can safely repair/remove the corresponding software? Why don't all software have a copy of their installion files here?

For example, I have full version of Macrium reflect on my PC. When I installed its WinPE recovery environment, it installed in the C:\Boot\Macrium folder, about 130 MB in size. However, two instances of the its .msi installer, about 120 MB each are copied to this windows\installer folder! It appears to be a waste of free space. I personally do not like to have extra stuff on my C partition. So did Macrium put a copy here or was it Windows doing?

Any info will be appreciated.

 

Yes.

Not all software installs in the same manner or makes use of the Windows Installer and .msi files, nor requires to keep a file in that folder.

I suppose you could say Windows and Macrium 'conspired' to put a file there, if you want to look at it that way.

I couldn't tell you directly why there are two Macrium files and/or if/why they would be identical.
This goes to my earlier suggestion that you be very judicious when/if removing anything there.

I think this link gives a fairly clear overview of what's up:

http://www.pcreview.co.uk/forums/safe-deleted-files-c-windows-installer-t211705.html

 

Thank you for taking the time for digging up these helpful links. As you must have gathered from the linked discussion that there is still a lot of confusion regarding whether it is safe to delete these files or not. Some say it is safe while others report problems.

The Microsoft cleanup utility mentioned has been discontinued by Microsoft in 2008 and I am not sure whether it is safe to use on Windows 7 SP1. I will just leave this folder alone for now. I usually do a clean format every 5-6 months anyway and the next clean install is due. That will take care of this folder.

Here are some more helpful links I found:

Safely delete orphaned patches

Information about msizap.exe

Microsoft article saying that cleanup tool containing msizap.exe has been discontinued

 

Unless there are some serious drive space issues, I would leave it alone.

 

I deleted mine a long time ago, and it never seemed of any problem due to that.

 

This is percisely what is causing confusion. Some people have had no problems but others have had serious problems after removing files from this folder.

Did you delete certain files or the entire folder?

What I plan to do is to make a backup of this folder using Macrium. Then I will use the msizap.exe with "g!" switch to remove the orphaned installers and patches. I will then see if everything is fine for a week or so. If something goes wrong I will just restore the folder from the backup.

 

There's 'confusion' because some people know what they're talking about and some don't. Like most anything else.

You can delete all those files and your software will continue to function normally.
Trying to run the program's uninstaller is where the problem will be. You'll get 'not a valid path', 'installer can't run' etc. messages, because you've removed the files that take care of that job.