Desktop went to Blue screen & began one continuous UNSTOPPABLE beep.
Removed the hard drive and tested it in an external drive case with my laptop, it's fine. Reinstalled it and got the BLUE-DEATH and BEEEEEEEEPPP again :mad:
Any opinions about what went wrong?

Have you tried an emergency boot disk?

Yes. Just got same blue/beep.

What if you remove the RAM? Make al different combinations if you have more than one, change them from the slots and verify they are properly installed... Also, you can try to remove the battery.

If the problem is not the HD or the RAM then I would say is the motherboard

Sounds like your ram might be damage try replacing it.