It is more likely that you have a fragmented C drive.

Defrag

There is a free version of a defrag program that is much better than the Windows built in defrag tool.

Defraggler from Piriform


http://www.piriform.com/defraggler

NOTE: Also make sure that the C drive still has enough free space to be able to work with temp files etc.

If the defrag program reports less than 15% freespsce, you are going to have to remove some things, either by copying to another drive or perhaps simply deleting them, BEFORE running defrag program of any kind.


--Mac