i am getting really annoyed by this . i have absolutely no idea why my computer has been hanging recently after login . i've installed all updates [minus SP1 + Genuine update] . OS: Windows 7 Ultimate 64Bit RAM: OCZ DDR2 2x2GB CPU: Phenom II x2 550BE Mobo: BioStar TA790GX 128M i've downgraded my BIOS to an older date because in the newer one , it would measure the NB temperature wrong . this is a fresh installation of Windows 7 , so i hardly have any programs installed [other than Messenger , Malware Bytes, MS Security Essentials and CoD4] . i've run Memtest already , and there were no errors/problems found . in addition to this , i get a constant I/O error on startup [will take note of error code after i restart later], and it takes a few restarts just so it would boot into Windows . are there any tests i can run to check if there are any problems on my HDD ? i am hoping it's not my HDD , but it's better to be safe then sorry by checking it .