Welcome to the windows7forums, everyone.
On the problem:
1. do not turn off indexing !
2. Try the repair option as Kemical has suggested and as it is illustrated here:
Windows 7 Startup Repair
(you may need to run it more than once)
If the repair option does not help, consider reinstalling 7, or recovering it from a backup if you have.
Skusal ste niekto na svojom PC zmerat jeho vykon s XP a potom s WIN 7?
Preco vsetci pisu ako madar?