Random reboots, heat issue?

I recently installed a few new parts into my computer and now it seems to be randomly rebooting/crashing. New things I installed were a motherboard, cpu and RAM. Everything seems to be installed fine, so I'm thinking it may be a problem with my cpu overheating, as I put the thermal paste on myself, and may have put a little too much/too less on it. So, as soon as one of these reboots happen when I check hardware monitor in bios, im getting a cpu temp of around 39C-40C, and MB temp of 34C-35C. The CPU temp seems pretty high for just booting up right? So do u think it could be my thermal paste job causing the heat? if so, any suggestions on applying it?

A few specifics please:

Where are you crashing/rebooting? Pre-POST, Post-POST, OS Load, etc?

Major hardware changes under Windows is going to require some work (Both before and after HW changes) involving reallocation of drivers etc. If its Windows thats you're having issues with, I would say you'd be better off with a clean install.

the crashing happens randomly in windows, I could be watching a movie, browsing the web, ect... But, I havnt had a crash while playing a game yet which seems odd. Also, I put a fresh install of windows on after putting in all the new hardware.

Is windows logging any errors? Research the Windows Event IDs in the Event Viewer. Right-click My Computer, Manage, Event viewer. From there I would suggest a memtest

well, the only thing i can see in the system event thing is a "Save Dump" saysThe computer has rebooted from a bugcheck, then aheap of ID stuff. As for a memcheck how do I go about doing one?

Just bumping so someone can help. Also just had a crash/reboot, and there is nothing in the event log that says why it happened.

You said you upgraded your motherboard. Did you reinstall windows?

Memtest86