Do I need to buy a new Power Supply Unit?

Yes you can...BUT..is the video card rated for the PSU you bought? in other words does the PSU have the wattage recommended buy the video card maker? you can get one of these at most any good computer shop...a href="http://www.newegg.com/Product/Product.aspx?Item=N82E16812196870&cm_re=4_pin_to_6_pin_pci_express-_-12-196-870-_-Product" rel="nofollow"http://www.newegg.com/Product/Product.as…/a