Time Machine running all the time

My time machine is running all the time when Parallels is active. I realize that for some reason it is backing up the virtual machine, but I would like it to back up the data from my Windows Vista sessions, but not the whole machine all the time. Is there a way to accomplish this without the danger of losing data in the virtual machine? I have a 400 GB partition space on my external drive for files that I want to backup but do not change.

 

Technically Time Machine can only backup the "entire" virtual machine since it's only a package of files. Those files changes all the time the VM is running.
So the only way to have a consistant time machine backup of a VM is to enable the "Smart Guard" option in the VM's configuration under "Backup". Then Parallels keeps a snapshot of the VM in the Backround that time machine can copy securely. Not perfect but I think the best solution given that time machine is not very smart and just copies all the files from A to Z... Have it a try!