The IDR boot media preparation wizard is trying to copy the tag files from the given OS installation CD media (or) given path to the IDR bootable CD image that it creates. Tag files are files such as "WIN51", "WIN51IA", "win51ia.SP1" etc that will be present at the root of the OS installation CD. If you are creating the IDR boot image from a path ( as opposed to a OS installation CD ), make sure that these files are present under the root of the path provided.
Joshua Kane
Symantec