|The biggest problem with trying to install a PCIe graphics card in one of these OEM PCs is the low wattage powersupplies they came with. Yours has only a 250W powersupply and it is probably insufficient to run your chosen graphics card.|
Your next problem may be that you need to enable the PCIe option in BIOS. It may be disabled by default.
Check your power requirements first then once you have a suitable replacement powersupply look at the bios settings.
The minimum PSU requirement for that graphics card is 450W. http://xfxforce.com/en-us/products/...
You should get something around 600W for safety and costing more than $50.
Goin' Fishin' (Some day)