Reset the BIOS by unplugging the PC from the power outlet.
Open the case so you see the Mobo. There is a button cell on it.
Remove it for one minute approx. Then reinsert it, check that the polarity is right.
And then plug in the PC and start the rig.
No need of removing everything first.
When and if it boot's it will most probably ask you to go to the BIOS.
If it does that, it means the processor is being recognized and atleast working until this level.
Just change the boot sequence in the BIOS to make the rig boot from the HDD first.
Press F10 , to save and exit after you have made the required changes.
The rig will boot up, keep pressing F8 as soon as you hear the POST Beep.
It will take you to the Windows Start Menu.
Choose Safe Mode and boot into it.
Let the rig start up completely and figure out the new processor. and adjust itself to it.
Then reboot the rig into normal windows....