I have a 2.8ghz Celeron D, will anything go wrong if I upgrade my video card?

i have a amd sempron 2.0 ghz and a ati 1650 pro with no problems so you should me fine. also its not really your processor (as longs as its above 2 ghz, which yours is) its more so your graphics slot so sense you have an agp slot an agp card should work fine but if i were you i would go with somthing bigger like an ati 3850 just make sure your psu can handle it