hello guys i need help from you.

i have ACER aspire 2920z with specification
intel Pentium dual core PROCESSOR t2390 (1.86 Ghz, 533 Mhz FSB, 1 mb L2 cache)
358 mb mobile intel graphic media accelerator x3100
2 gb ddr2 160 gb hdd
Bluetooth 2.0 +edr 802.11b/g wan
windows vista genuine 

here is my problem
before i turn on 2 to 3 times looping to STARTUP menu
1. safemode
2. safemode networking
3. safemode dos
4. normal windows

then when continue to windows it freezing there either 10 MINUTES or longer than that

i tried to repair how many times to reformat the drive c
i tried change operating system to win 7 but no change
i also tried win xp not changing still freezing
i tried to disable all the service and startup  in system configuration no change
i tried change dump memory to complete dump memory
i tried disable the microsof ACPI complaint control  method baterry
some time when i go to safemode freezing there SOMETIMES ok

waahhh its very hard to fix this problem maybe hardware problem

guyss i need your suggestion as soon as possible

thank you very much in advance waiting for your respond