Is your computer a HP Pavilion w5040la
? That was the result I got when I searched your model number at www.hp.com.
If it is then you only have three PCI expansion slots but no PCI-E or AGP slots for a graphics card. One of the major problems with companies like HP or Dell is that they do anything that they can to shave off cost. Things like getting rid of expansion slots and therefore upgradeability. If it was some company other than HP you might be able to replace the motherboard, but HP doesn't use standard sized parts or cases. Sorry, but you will probably have to return that card for a refund if you can.