Windows

Crackers are not trustworthy and can insert things that will turn your system into a Zombie or worse.

In this case by your description there seems to be something inserted to Crack your ASUS BIOS ands change it to suit their needs not yours. So you basically get exactly what you pay for.

Col

Heh kind of funny I just got finshed writing to a guy that had almost the same problem as you.. Here are my suggestions,

1: Your copy of Vista is bugged now I download alot of things form PARADOX and I have yet to have problems but hey you never know.

2: Bad Power Supply if you are putting to much stress on you PS that could be one of the big issues. If your PS doesnt have enough watts its going to overload and eather 1) shut down or 2) go POOF I would suggest having at least a 500 to 600 watt for that quad core and depending on the GFX card ((Nvidias 7800 to 8800 graphics cards do take alot of power)
that might be another reason you PS is overloaded

3) Try your RAM one bad MEM sector could cause the entire thing just to restart check it with a Mem tester

4) Bad sectors on your HDD or just a bad HDD in all Seagates a good company if I am correct you should have got a CD with your Hard Drive and on it it should have a tester.

5) Run a scan disk FROM DOS not windows you need to do a full scan I think the command is chkdsk /p or /r one or the other it will work best just to do both of them because the p is partition and the r is repair ((ones longer and the other shorter))

6) depending on how long it will run try doing a full Defrag you never know

and well if all else fails just scream at the top of your lungs and kick it because from there on in it could be a million more issues such as CPU is bad, Moterboard is bad, could be your DVD burner thats causing it, might be a small issue form your headers, might be something you have in your USB so on and so on..

Ahh two more things as for your last question yes you still have to install the ASUS OEM BIOS but because its Vista which I dont work with its your call expermint to see if anything changes or not and second if you have the chance make a full backup of your HDD onto another HDD because I had this before and never thought anything of it untill one day it never booted into windows just wanted to give you a heads up on that so if or it does happen you are already ahead of the game.

hopfully this helps you..