Its in the instructions, also read the instructions at:

https://moi3d.com/forum/messages.php?webtag=MOI&msg=10465.1

The "Roaming folder" is your:
C:\Users\"YOUR user name"\AppData\Roaming\ as it is for all Win apps...

There you will find the "Moi Backup-YOURUSERNAME" Folder, it's your original setup.

Just delete the Moi folder there and rename the "Moi Backup-YOURUSERNAME" folder to "Moi" and you're back to your original...

Please read through all the stuff on the link above, any further questions, please post them there...