Windows xp laptop freezing

Hi, my windows xp laptop freezes on startup to the point that not even the power button will turn it off. I can startup in safe mode and have done disk checks, defrags virus scans registry scans and nothing worked. I have even reinstalled windows xp and formated the hard drive. The computer is still freezing at startup. any suggestions would be appreciated.

 

Could you give us more information such as the make and model of the laptop and whether you're running 32-bit or 64-bit XP and which service pack? What's showing on the display when the laptop freezes?

 

Check ram sticks one at a time.

 

Acer 3004LCi
Windows XP 32bit Service pack 3
It loads the explorer just fine but then becomes non-responsive

 

Are you referring to Internet Explorer? If so, what version?

If it is Windows Explorer instead, and you reinstalled Windows, have you considered the possibility that Windows as well as your security programs are trying to update and might be causing the apparent freeze?