Gtx 750 ti installing problem

[a77]

Today i bought a new msi gtx 750 ti and when i first installed the drivers..it installed correctly..but after rebooting my pc...i checked on dxdiag it shows only the dedicated gpu..also before i rebooted my pc..i checked in dxdiag.then it was showing gtx 750 ti..when i tried to re-intall driver it shows the driver could not find a compatible hardware? Plz reply fast..
Specification
msi g41m p33 combo motheboard
core 2 duo
Msi gtx 750 ti 2gb
4gb ddr3 RAM
500 watt psu (from unknown company)

 

[ronintexas]

It could be one of two things:
1) Check your BIOS - make sure that the 750ti is your primary GPU (there should be a default GPU setting in the BIOS - usually something like "PCI, PCIe, on-board - select PCI or PCIe depending on the slot your card is in).
2) The PSU may not be providing enough power - minimum for the 750ti is 400W - so it should handle it, but not all PSUs are made equal.