KB900325\update.inf: [Prerequisite] condition = SingleOp , PreReq.SingleOp.MediaCenter condition = SingleOp , PreReq.SingleOp.OneDotOneFramework condition = SingleOp , PreReq.SingleOp.OneDotOneSP1Framework [PreReq.SingleOp.MediaCenter] EqualOp = CheckCustom,,SpCustom.dll,IsMediaCenterPC,,"==",1 [PreReq.SingleOp.OneDotOneFramework] EqualOp = CheckReg, HKLM, "SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322", "Install", 0x00010001, "==", "1" [PreReq.SingleOp.OneDotOneSP1Framework] GreatOrEqualOp = CheckReg, HKLM, "SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322", "SP", 0x00010001, ">=", "1"