Related Question:
Why does the /winsxs folder grow so large, and can it be made smaller?
My server 2008 installation drive is eating space like anything. Specially the winsxs folder.
Trying compress it results in a “file/folder is currently accessed” error.
Any suggestions to free up hard disk space?
For winsxs see this article. The most relevant part is:
The Winsxs folder, stores multiple copies of dll's in order to let multiple applications run in Windows without any compatibility problem.
My advice is not to touch this folder. It's essential for Windows.
The only general advice for saving space is to uninstall the Windows software that you don't need. Anything else is dangerous grounds.
EDIT
You can, however, delete the contents of the Windows temporary files directory at C:\Windows\Temp.
