If I had to guess just based on the specs you gave (since its an old prebuilt Dell) I'd say no. Chances are that either a.) The power supply is too weak, or b.) There's no PCI express slot on your motherboard (which a newer video card requires). Some HD 4600 series cards were made for a different, older interface called AGP.
If you could make sure the power supply was adequate and that you had a PCI express slot on your motherboard, then a GTX 460 would work.