I'm running XP

Recently....I was browsing the net (Firefox), and it locked up my entire system...but only certain things, like my mouse arrow could move around, but I couldn't even access the menu doing "Ctrl Alt Del" or even get the START Menu to come up, I had to eventually COLD boot my system.

This happened TWO times...but the common denominator here is...I was watching Embedded Videos at the time (Be it Youtube or something)

As a result, I lost ALL my book marks, yes the malfunction wiped them clean for some reason don't know why.

Anyone know how this can happen?