Windows won't install hangs at starting windows logo...Please Help!

Okay so I may have buggered something up royally, but I took the CPU out of my mom's computer. Ended up dusting it out, because it was overheating. I wanted to try the phenom out in my board so I swapped them out. It is an HP pavilion a6755y se. I put an Athlon x2 in it and it wouldn't post. I took it out and put the phenom back in and now it won't boot to windows. I reformatted the entire drive and to no avail it still didn't work. I disconnected all USB's attached and I am using a PS/2 mouse and keyboard. This is really frustrating to me. It loaded the default bios settings from when I took the CMOS battery out. Had to change the Sata controller to IDE. When put on ACHI it gave me a screen full of colorful boxes that flashed and really scared me. I am very frustrated and I am wondering where I should go from here. My mom is pissed and she wants her computer back to normal condition. If anyone could help me it would be excellent. I call myself resetting the CMOS, moving the jumper cap over then back to its original spot. Dunno how to flash the bios. It reads all the ram and the phenom that is in its socket so I don't think it's a hardware issue. Although, I can't get a livecd to run for the life of me. I dunno what I have done, but I would like to fix it asap even if it needs new parts. It did take quite a bit of force to get the heatsink off the cpu when I was dusting. Never came out though while locked in place so I don't think it's bent pins.Tech Specs:http://www1.hp.com/ewfrf/wc/document...t=3870521#N259

If you change the processor on an OEM system, it might have some effect on the OEM operating system, but not sure.

If a system boots to the Windows Logo and stops, it might be a driver problem. Will it boot in Safe Mode?

I am not familiar with AMD processors, but are the ones you have changed around compatible with those motherboards?

Are you experienced with changing processors and memory and know how to protect from static electricity damage? Did you reapply any heat sink compound when you reinstalled?

Yes i discharged myself to the case before taking out the processor. I am trying to figure out why it just freezes and will go no further. It doesnt have an os currently installed as the hdd is still very fresh. all the ram and cpu is recognized on the bios boot. I will also try reapplying some more thermal paste. Any help in the meantime would be great. thanks for your reply too.

You may not need to apply more thermal paste. Use your judgement..to much can also hurt.

If nothing seems to work, perhaps you dislodged some connections inside the case.

If the system boots, then you should be able to boot to install DVD, or at least some DVD. Saying you cannot boot to a Live CD/DVD and run Linux is not a good sign.