Your welcome. Thankfully we have forums to help us out when we mess up, used this and other ones plenty of times myself for help on things I don't know much about, so nice to give back when I can.
Well anyway, you could try putting the CPU back in properly if you can straighten the pins without breaking any? Separate the cpu from the heatsink, thermal paste is all that attaches them.
- Clean off the thermal paste from the top of the cpu. Use a slightly damp microfibre cloth to wipe it away. Do the same for the remaining paste left on your heatsink. Lastly use a little iisopropyl alcohol to clean the now bare metal flat top of the CPU and again some more to finish cleaning the heatsink of any residue. Don't use any other cleaners, isopropyl alcohol is perfect as it evaporates away safely after use. When done no more touching those surfaces!
- If you can then get the cpu back into the motherboard socket? Lever raised when putting in, remember the corner arrow's on cpu and board to get the cpu in the correct way, then lever down to secure the cpu into the motherboard. Shouldn't take much force to lock it, so if it's struggling something's not lined up right.
- Now you need to reapply a thin layer of new thermal paste (arctic silver is good stuff), you need to use something like an old credit card to spread it so it's just a light thin layer completely covering the top metal surface of the cpu.
- Lastly reattach the heatsink onto the cpu and secure it to the bracket on the motherboard so the heatsink stays in it's place. Then put reconnect the fan power and control lead to the motherboard and plug everything back in to test.
Now if it's dead, you're probably better off getting a newer pc than wasting money on another CPU and more memory. That's quite an old board now and won't support the latest CPU's. Yours has old DDR2 memory slots as well, DDR3 is common place, with DDR4 being the most recent.
If you've no budget for a new one, you could go on ebay for a cheap replacement cpu and hope the cpu is the only thing that's been damaged. Ramming the CPU in badly and trying to boot the pc may possibly of killed the motherboard too.
Helpful videos:
Fitting the CPU -
Spreading new thermal paste -
People seem to be preferring the pea in the middle method, I personally like to spread it but I'm quite meticulous when it comes to getting an even smooth coating where as the spreads I see on youtube are a right slapdash job.