The Pentium Dual Core E2140 works with 945g chipset MB, but some of old MB with pcie1.1x16 does not compatible with the pcie2.1X16 GPU (Only for the AMD HD GPU). And if that MB has the BIOS update then the 2.1X16 GPU will compatible with the MB. You can google that "pcie1.1X16 GPU on pcie2.1X16", you can see somebody say yes, somebody other say not. I recommend check there is the bios update or buy the NVidia card.