I have a compaq Presario with Vista. When I try to burn a CD on itunes I get a warning note. "the registry settings used by itunes for importing and burning CDs are missing. This can happen as a result of installing other cd burning software. Please reinstall itunes". I have not install new software but an HP tech did some work on my PC and may have activated other software. How can I get it back to itunes? HP nor Apple have been of any help.