But wouldn't a power supply issue not be dependent on certain applications being in use?
It got to the point I could start and stop the beeping by opening and closing certain applications or web pages.
I wouldn't disagree that a heftier power supply could be beneficial however, the replacement video card has added yet another fan to the unit.
If the PSU is starting to go south then small variances in the outputs COULD be picked up by the motherboard and then the beeping could start.
To take satcos' suggestion further, what is the make/model of the computer or the make/model of the motherboard (if you didn't buy a "brand name" system and built your own)? Let us know that and I'll see what I can dig up.