I have an old P4 machine that I'm trying to breathe new life into with a cheap motherboard/gpu upgrade. I've taken it all apart, but can't figure out how to get the old heatsink off so I can move it and the CPU over to the new motherboard. Pushing here, pulling there, even a gentle twist - nothing. Google's been nearly useless - every P4 heatsink guide I find has simple-looking clasps, nothing pictured is like this thing. Has anyone seen this before?



More views: http://img21.imageshack.us/gal.php?g=p4heatsink004.jpg

Those metal tabs on the left have stirrups below them which attach to horizontal black plastic posts on the mounting bracket. Push them down (harder than you'd think) and lever them so the stirrups come off the posts.

Well that was embarrassingly easy. Thanks!