For the few couple months I have been having serious PC CPU overheating issues. The heatsink FELT secure, but I ignored it and fretted over it and was just dumb.
Tonight I pulled the heat sink, removed the old thermal paste, reapplied some thermal paste I've had since 2002, and now I am running 30 degrees cooler. I was at about 80C in Mechwarrior... just played a game maxing out at 50C.
Point of this post is that thermal paste lasts a long time if stored properly. Also I hate the heatsink style for the i7 chips. There are arrows on the corner posts that are counter-intuitive. Apparently you turn toward the arrow to LOOSEN it.