So, my son has an old dell desktop model with Intel Core 2 duo E8500 3.16 ghz. and windows 8.1. He currently has ATI Radeon HD 4600 Graphics card and it needs to be upgraded. I'm not the greatest at computers so need some help figuring out what graphics card will work for his PC. Any information would be greatly appreciated and I can give additional info if its needed. Thank you for you time.