Also try an eBay store called upgradeyourlaptop. If you search for one of their cards there will be a link in the description which will take you to all alienware machines and modded drivers for all of the cards. It's come in handy a few times for me. There will be an R4 with 700 series driver there. Should be easy as pie. Worked easy with my M18x R2 which is the same gen as your R4.