if scanning and all the previous solutions we suggested didnt work then try to reformat your hard disk its the last desperate solution u can only make a back-up for your game sources only.
GiftsMy Specs:
Intel(R) Core(TM) i7 CPU 860@2.80GHz (8CPU)
2.00GB RAMs DDR3
Windows 7 Home Premium SP1
ATI HD4670 1770MBs
1.2TB Hard Disk