Here is the page with my pc specs: http://h10025.www1.hp.com/ewfrf/wc/prodinfoCategory?lc=en&cc=us&dlc=en&product=471644&lang=en& I Installed a Chaintech Geforce 6600 video card and was pretty sure it is compatible with the system. First of all, when I plugged the monitor into the new card, I got a blank screen. I then plugged it back into the old card and it worked fine. I have SIS760 integrated video. After some research I disabled the SIS display adapter in device manager and rebooted....blank screen with new card. I then went into bios and switched the setting from "PCI" to "AGP/onboard". (confusing since my new card is AGP, and I do not want onboard!!) Blank screen. Finally, I removed the old drivers (I was reluctant to do this at first). My fears were confirmed when I rebooted. I got a blank screen no matter where I plugged in my monitor. All I got was 1 long beep and two short ones. (Video error code). I then removed the new card and rebooted. I was then able to see again thank god; I re-enabled the sis display adapter and rebooted which resulted in my pc freezing every time windows started up. I then booted in safe mode and turned the display adaptor off again and windows loads fine (I suppose removing the drivers was the cause of the freezing). I am now stuck wondering what on earth to do. I have read about people needing to do something with jumpers and power supply, but I know nothing about that stuff and do not want to start messing around if I am not sure what I am doing; as it is I have had to turn off my computer unsafely too many times. Any help would be appreciated...thanks. Edit: I forgot to add that after I installed the card...I tried the driver installation disk...which resulted in an error message saying that Nvidia could not locate any drivers compatible with my current hardware; this was not surprising considering my computer refused to acknowledge that the card was even installed.