You can find the system specs of the pc here, http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&cc=us&dest_page=product&dlc=en&product=93212&docname=c00009492. What I was trying to do was install a new graphics card in the agp slot. The video card I was trying to install was a PNY 6600. But It didn't work. I first tried to uninstall the vanta graphics card in the add/remove programs, but It wasn't displayed. So I went into the device manager and tried to uninstall it that way and it worked and I had to restart the pc. (note there is another issue that shows itself when i shut down the pc that is discussed in another thread). Yet when the pc restarts a windows message says a new device was found and it automatically installs the drivers for the vanta card like they are in its database. After this happened, i just shut down the pc and proceeded to remove the vanta card and install the pny geforce 6600. I made sure the card had power through the molex power cable and i put the case back together and proceeded to turn it on. But an error message was shown before i could even get into bios and it told me to check the video card by removing it from the pc to see if the problem persists. Which I did and guess what.... the problem persisted. So now I reinstalled the vanta card and everything is working again. Could it have something to do with the agp slot only being x4, or could molex power cables go bad and thus it wouldn't get any power (noted by the fact that the fan wasn't spinning) or it may have to do something with the problem noted above in parenthesis and in another thread. Other than those, I have no idea why it didn't work.