I need computer help. My pc is running so slow it is a HP 6130 pavillion?

i have a amp 64x2 duel core proc.5000+ 2.6ghz. 3gb ram 32 bit oper sys. my graphics driver is a nvidia gforce 6150senforce430. well i do screenprinting and embroidery im running corel drawx4, corel drawings (a didgitizing program for embroidery, software that does virtual samples, and an embroidery machine. Everything else for the most part is off my pc, but lately it runs websites slow, it closes my prograns or just make then not respond. Im thinking its my processor, I show 90% available hard disk available. I have ran every virus test and pc tools and pc DR. and HP system testa and everything is coming back ok, im stumped. Could it be my processor???