Did my old Os on a new mb kill my cpu?

It is really really hard to kill a working processor, especially with software. The only chance would be if you left the PC on doing stress testing overnight, but even then that is unlikely with your 6 hrs 45c report.

I would be more willing to believe that using the old OS on the new board killed the new board.

It is STRONGLY recommended that you not try to keep an OS when you change motherboards. ESPECIALLY when you are changing to a different motherboard maker.

The first thing I would try to do if I were you is to take the battery out for 30 minutes and put it back in, then try to boot it up again.

- Edit - BTW, what do you mean you tested PSU, RAM, and video card? Did you try these in a 2nd PC?

i did reset the bios (properly).i fell asleep watching a movie with nothing else running.i was worried when it started running windows with the old chipset drivers but after installing the 990fx drivers i thought i was safe especially after stress testing it.everything seems to work fine but no video and the cpu diognostic led is on.And yes tested in a different computer thats not mine.but they (understandably)dont want me taking out their cpu.just wish i knew for sure before RMAing the mb just to find out i fried my cpu.and thanx 4 the fast response

Unless you try a different processor or a different motherboard, you are going to have a tough time getting a definitive answer either way.

You could buy a cheap sempron that fits the slot for probably about $20 on ebay. That is probably the cheapest definitive test you can do.