p.s.: maybe this has nothing to do with my problem, but some days ago I deleted some files from windows folder...I was following the instructions on this page (only first few numbers):
[GUIDE]: Making your windows folder smaller! - Neowin Forums
Quote of the "interesting" instructions:
5. c:\windows\driver cache\i386\
NOTE: DONíT DELETE THIS FOLDER, JUST ALL THE FILES INSIDE! This is one you may not want to delete, this takes up a bit of space (about 80mb) but windows uses if you ever add or remove windows components and things like printer drivers. If youíre your hardware is already working fine, you donít need this folder on your hard drive. For example, if you delete this folder, and try to install IIS, windows will ask for the CD or Network share with the files on it, if you donít need to add or remove windows components often, deleting this will free up some space for you.