rgd1101 :
no. don't turn on the laptop without thermal paste. bad thermal paste is better than no thermal paste
That's incorrect. Bad thermal paste is worse than no thermal paste. The vast majority of the heat transfer from the CPU to the heatsink is via metal-on-metal contact. With no thermal paste, the metal-on-metal contact is still there, you just have a lot of air gaps with poor thermal conductivity.
A bad paste job (too much paste) gets rid of the air gaps, but it also gets rid of the metal-on-metal contact. So a bad paste job can do a lot more harm than it does good.
Your CPU will run hotter without paste than with, but it will still run.
http
/www.hardwaresecrets.com/thermal-compound-roundup-february-2012/5/
All modern CPUs are designed to throttle themselves if they sense they're overheating, to prevent damage. In fact a video demonstrating this very thing was one of the things which first made Tom's Hardware famous on the Internet. (The video was made back when Intel first introduced this thermal protection throttling, and compared to AMD CPUs which didn't have it.)
https/www.youtube.com/watch?v=Xf0VuRG7MN4
Don't fret about which paste to buy - all are nearly equally effective. The slight difference between the expensive brands isn't worth the extra price unless you're a builder who insists on having the absolute best. Just be sure to apply it properly - put a very small dollap (about a half-pea size), then squish it down and around until you fee the heatsink's surface grinding on the CPU's surface. That's when you know you have metal-on-metal contact. Then strap the whole thing down (the compression is necessary to slightly deform the tips of the metal ridges and increase metal-on-metal contact).