Protected mode boot failure

[Guest]

Heres a weird one. I had boot problems with my PC, so in a panic connected my HD to a friends PC to copy data off it.
This worked fine. I then put my HD back in my system, and now BOTH PCs have the same weird problem.Basically my machine will rarely boot up. It hangs just before changing to the windows desktop (still at the post logo black screen). I can alwasy boot into safe mode, and if i tick that box that disables 32bit protected mode drivers it boots fine, but in compatibility mode for the hard disk.I thought it must be a virus/driver prob, so did a major virus scan, then actually reinstalled the operating system in a new directory. No change. I also tried using standard generic drivers for the hard disk, and everything else I can think of. Surely it must be a hardware prob? but then why the same thing suddenly on my friends PC?
This is driving me mental, any help VASTLY appreciated.

 

[Raistlin]

can we say virus or virii?

"(

Bored,Certified Tech

 

[Guest]

Hi Cliff, sounds like you could have a virus that attacked your bios, nasty little creatures all, remember thst not all virus protection picks up all viruses, and if your friends sys was working fine and now isnt, then it will be something you gave him, Norton is regarded as one of the better Anti virus protection, but Vet is very good also

 

[Guest]

Yeah i bit the bullet and fdisked and formatted, still no change, so then i realised i needed to fdisk /mbr. This seemed to fix the problem, although its happened again once since, and a diagnostic prog i got said it couldnt read my BIOS. Are we talking the motherboard BIOS here? if so, i take it reflashing the BIOS should kill it ok yes?
Thanks for the suggestions guys, the board is VERY helpfull