My pc has been slow lately

[asparagus]

my pc is running well but lately it started to boot slow first.
then while im playing my game it started to be hang.
then the blue screen of death some of you call appears then restart.
then its always like that, it boots for about 20mins. then loads up for another 15mins. then programs in my computer runs slow.
so ive to decided to clean the registry first, defrag my disk
but still the same. ive looked for bad sectors and repair it.
but still the same.
so now ive tried to reformat my hard disk completely.
but it still runs slow.
i have a 3.2gb of ddr ram
a 500gb WD hard disk
and an amd phenomx4 processor.

what do you think is the problem and what can i do?

 

[tuddler]

Hi... you guys still here, I'm experiencing the problem that asparagus had... After some windows update in my windows 7, blue screen of death appears, and after that all my games became so slow... My FPS in most of the games i played became 10 or 15 only... I tested it in my nba 2k12 and nba 2k11, and both of them gave me same FPS... Is this also a HDD issue???? Pls help me, and sorry if my grammar is bad....