Cool.
First, make sure your game list window is open, and all filters reset.
File menu:
Maintenance/Delete twin games
The default settings should be ok
Click Delete Games
Depending your on pc speed, this can take up to a few minutes.
Go to game list window, it should now contain games marked for deletion. (normally you should see a 'D' in the flag column.)
Right click on any game, and from the drop down menu select 'Delete all games in filter'
Go back to maintenance menu, and select compact database. Select Compact game file.
That should do it :)
I maintain a large database and I get games from various sources. However I would like to look for multiple games and then remove them. How to do that?