JFMuggs, your PIDChecker is wrong. I just installed this key on Win7 Ultimate 7600.16385. slmgr -dlv says "Windows(R) 7, OEM_SLP channel" Computer Properties now says "Product ID: 00426-OEM-8992662-00497" Still not activated because I need SLIC2.1 bios mod and certificate (is there a Dell 2.1 cert leaked yet?) edit: oh wow, i just noticed the guy who posted above me, will have to try that later tonight