Glad I could help, glad your machine is back in working order (buying a new one is never fun or cheap)

One Long and Two Short Beeps Video (Mono/CGA Display Circuitry) issue.

have your video card tested. make sure it is seated properly. video card shorts are one of the most common issues with...

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

was the update you did service pack 3?
if yes you need to unplug all usb ports, disconnect any secondary hdd and reboot with ONLY the primary HDD running.

this is a known issue for SP3 and a fix...