I doubt that your new CPU is causing the issues, because the BIOS is run by the motherboard to initialize the other system components. Since you have upgraded the BIOS (correct?), I would pull the power plug from the PSU, remove the CMOS battery for a few minutes, then install a new CMOS battery (they only last about 3 years) and boot up again into the BIOS. You should be able to set the time and date in the BIOS before attempting to boot into Windows.
If you have not upgraded your motherboard's BIOS, then use your old CPU to get it working again and flash to the latest BIOS posted for your motherboard. Do the same thing about clearing the CMOS memory of old settings too.
As Albert Einstein said, "I could have done so much more with a Big Al's Computer!".