Previously i was using xp which got virus and half of my whole hard disk of different drives became empty. then i formatted C: and installed windows 7 ultimate 32bit. after about its 1 week, D: drive got access denied. permission was of full control so i did chkdsk. yes, it worked and later again same problem. Now i got same error on all drives (except c: till now) including usb drive. when i do chkdsk it works and after 10min or 1 hr or 2-3 days same problem. i did full chkdsk and virus scan but nothing found. please help