Wine stores data in a directory called ".wine", all settings, registry entries, etc will be there, installed apps should all be in its subdirs. The simplest way would be to move/rename the ".wine" directory into e.g. ".wineold". If you then start wine, it will create a new ".wine" directory, where you can install new apps. Later you can move the ".wineold" directory back to ".wine", which will restore the old state of your wine installation. You can choose the default directory to be used by wine by putting an environment variable before a command, if you'd want to run an app in ".wineold", it would look like WINEPREFIX=.wineold wine xyz.exe All this comes without warranty, please be careful with moving or deleting data, and please don't blame me, if something goes wrong.
