I ran the disk compression routine when parallels suggested I do so, and after running it the virtual machine gave me a disk access error. I went looking for the .pvm file and it was gone! I have backups in both Time machine and Super Duper but where in my Mac directory structure do I put it back? Also, parallels Tools will not install. The thing has worked well up to now but it appears to have gone awry in the last few days, with no unusual events to ascribe the changes to!
Time machine automatically sets back the file in the right place. See also topic http://forum.parallels.com/showthread.php?t=107483
Marvelous! Thanks for your help. Worked like a charm. First time I have ever had to resort to a backup. On the build number issue I'm still using XP so maybe I'm immune. Have Parallels on 2 machines with XP and except for this incident all has been well. Again, thanks. I'm an artist not a techie so I'm lost in this stuff.