Thermal Paste life
Yes, whenever you remove the cooler you should reapply the paste as there will now be air pockets which wont transfer heat as well as the paste does.
When putting my new computer together, I applied a heatsink which had some thermal paste already applied on it, so I put it on top of my cpu and screwed it down. A while later the psu died, so I disassembled the entire computer to ship back the psu and case. Right now the heatsink and cpu are sitting in boxes, and I was wondering, will I need to wipe off and reapply the thermal paste when I reassemble to computer? This is a high-end cooler, so I assume whatever they put on at the factory is pretty supremo stuff.
If so, any good guides for doing it for processors? I've done it a few times before for xbox360 chips, but I'm not too confident in the steps I take.