Seeing this on my work PC one afternoon prompted me for an early coffee break. It could take a while for my 3 year old (or maybe even older as the IT dep't in our company doesn't give users info on the real age of the machine) Lenovo black box running Windows XP Professional on a 2.6 GHz Intel Core 2 with 2 GB RAM to come back around.
Caused by some programming shenanigan that proved way beyond what the machine could handle?
I was editing a document in MS Word 2003.
My hackintoshed Mini 1000 (when it was alive) and Mini 311, I could very well forgive when it gave kernel panics - hey, they're not even meant to run Mac OS X Snow Leopard in the first place. Sometimes they would come up conscious from that reverie that I had conjured up for them, remembering for a while that they're PC's and not Macs.
Oh and coffee from the pantry wasn't of any help.