computers will boot through POST without a HDD. a failing HDD will rarely cause POST error beeps

8 step process to computer repair.

1: make sure pc is plugged in tightly and directly to a wall outlet (extensions are often not properly grounded)
2:look inside the box and make sure no loose...

count the beeps for us.

1 Short Beep Normal POST, computer is ok.
2 Short Beep POST error, review screen for error code.

Continuous Beep No Power, Loose Card, or Short.
Repeating Short...

long beeps, short beeps or one continuous beep?

long beep: short somwhere
short beeps: memory
continuous beep: video card