There is an easy way to achieve that.
MediaMonkey library data files are .MDB (Microsoft Access DataBase) files stored in MM\Data folder. By make one or several copies of it, you'll be able to have multiple versions of the database (backups).
First of all, make sure MediaMonkey is closed.
With Explorer, goto the folder that contains MediaMonkey, and do a copy
of the library folder. By example:
"C:\Program Files\MediaMonkey\Data"
copied to
"C:\Program Files\MediaMonkey\Data (complete)"
Then open MediaMonkey and scan whatever you want. You can even delete the entire library first (File->Clear Library) if you want, since you have a backup of it.
When you have finished to tag your files, close MM and go back to Explorer. If you don't need the database (library) you just worked on, delete the
Data folder. If you want to keep it to work with another time, rename it to something else, like
"Data (2005-07-12)"Rename the folder previously renamed, back to
Data:
"C:\Program Files\MediaMonkey\Data (complete)"
renamed to
"C:\Program Files\MediaMonkey\Data"
Open MediaMonkey again, and you're back with your original library!
Nice day, isn't it?
Eyal