"Either the hard disk has no volumes or its file system is not supported or contains errors. Start your virtual machine and check the disk for file system errors." That's the text of the error message that opens when I attempt to mount any of the VMs I have - Ubuntu, Windows XP or 7. The XP install is a fresh one, which did seem to open at first, but subsequently now doesn't, can't comment on the others. There's nothing wrong with the file system or anything else that I know of. What next, please? Parallels 6.0.11992, Mac Pro, 6-Core Intel Xeon 3.33 GHz, 6 cores, 6G memory, ATI HD 5870 video card.