How to restore wine configuration to default?

You should be able to rename ~/.wine to ~/.wine.backup and then run the wine configuration program from the menu or from the command-line (winecfg) and then a new ~/.wine will be regenerated and you will still have the old wine folder and so all your files will remain. You can then decide how to proceed.

Additionally, sometimes the old WINEPREFIX can be fixed by resetting the dll overrides, with winetricks alldlls=default, as those overrides can often cause problems, as I discuss in this answer.

Problems with wine can often occur, and that is why I always recommend installing new games or applications in their own WINEPREFIX, as I discuss here:

• How to reset setting of Wine, avoiding uninstalling all applications in it?