What I have?

I have installed Windows Server 2003 with following details:

OS installed in: C drive

Space allocated to C drive: 50GB


Important space consuming software installed: Visual studio 2005 & 2008, Office 2007, MOSS 2007 and SQL Server 2005

C:\Program Files folder size is around 9GB

C:\Documents and Settings folder size is around 2GB

What problem am I facing?

When I see properties of C:\Windows folder (by right clicking ON the folder), it shows the size as 32GB. But, if I open C:\Windows folder in Windows Explorer, select all files & folder (including hidden ones) and go to properties dialog, it shows about 7GB!

But, my C drive is running out of memory often and I am not able to find what is consuming the rest 25GB of space.

Can anyone help me in cleaning up my C drive?

Thanks in advance!


After Raintree' suggestion, I found out that the folder, C:\WINDOWS\Installer is consuming around 29GB of space.

Is it fine to clear this folder?

4 Answers 4


Did you also uncheck "Hide protected operating system files," also found under Tools, Folder Options, View?


The %windir%\Installer (C:\Windows\Installer in your case) folder is used by Windows Installer to cache MSI files and their associated files, such as MSPs. If you delete the contents of this folder, you may not be able to run repair or uninstall operations on your installed programs without the original program media (CD, download file) present.

  • Removing the folders and files will cause headache later when you want to uninstall some programs. I suggest you to do an NTFS compression of the whole "Installer" folder.
    – deddebme
    Jan 7, 2010 at 19:55

Try using a program like TreeSize free on the C:\Windows\Installer folder to see exactly what files/folders are using so much storage space.



As Jay Michaud says, the Installer folder is not really a good idea to clear out. Emptying it will in many cases prevent the installs of service packs or other patches, as well as the removal of some existing installations. That doesn't mean that everything there is actually any good, as the folder has a tendency to accumulate duplicate files when installations fail and are re-downloaded, and also when you uninstall things the Installer entries often remain. I have on numerous occasions simply moved some of the files elsewhere with more space, and copied them back when an install needed them. But it's not easy to find out which ones are needed - took me a while.

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