Umm what is yumi and WHAT have you tried? If they are legal copies then why are you creating iso's? After some googling (Because you failed to say what you meant by yumi) I think I know what you are talking about. But since you somehow have "Legal" copies that are not .iso's (Which is the only way they would be if they were truly legal.) Digital river downloads AND official MS disks would work and not HAVE to be made into iso's. But since we are on the issue of legal have you tried the OFFICIAL ms tool for this? http://www.microsoftstore.com/store/msstore/html/pbPage.Help_Win7_usbdvd_dwnTool