For anyone that has this problem, in my case it was a prgram called DVD43 that was the cause. Nothing wrong with Windows or the hardware. It's a region free/CSS free program.

Cheers

FYI, That didnt work.

I reformatted and loaded XP back on and the problem was fixed (along with a few others).

I have a full copy of nero 6 and what i thought was a full copy of nero 7. I...

Pardon my ignorance, but you mean i should delete them both permanently?

My problem mirrors the first example exactly.

The autorun thing didnt work as it was already set to 1.

Is reinstalling XP the only option?