XP won't load - keeps rebooting

[dareutwo]

I don't know exactly what happened.
Can't boot into safe mode even
As per the update, the window popped up saying windows updates are ready, click ok, then went to the store. I came back and the comp was on the boot screen.
No biggy, something to work on over morning coffee.
All the real data is on a seperate partitioned h/d. So even if I have to completely reformat C I won't lose anything important.