Keep pressing F8 during start up to enter boot menu (if you reached Windows logo you're too late). Go into Safe Mode with it (try Safe Mode with Networking first). From there you should be able to do what's needed.
If you are absolutely sure you are booting into the Windows DVD (as in you are prompted to press a key to boot into the DVD) and it's crashing, that means you have failed hardware. You'll need to run a few hardware tests using something like the UBCD
to help find out which piece of hardware has failed. Some to use:
- Memory - Memtest86+ : 7+ passes
- CPU - Prime95 (Mersenne Prime Test) : 9+ hours. Note you will need UBCD 5.0.1 or older, anything newer will most likely crash.
- GPU - Video Memory Stress Test (under Peripherals) - one full pass.
Obviously, because this is happening even when loading DVD, the problematic hardware is not
your hard drive(s). It has to be CPU, RAM, Motherboard or Power Supply, with graphics card a slight chance. Most likely you just have very bad RAM or it is unsupported by your motherboard.