Schau mal bitte in die
FAQ:
If I want to go back to original state but I forgot the tweaks I've installed, what can I do?
It doesn't matter, if you choose tweaks for uninstalling, that you haven't installed.
If the uninstaller don't find a backup, it will copy the original files from USB drive over your original files of your MZD system, so nothing has really changed after that.
BUT: YOU SHOULD NOT DO THIS FOR NEW AND UNKNOWN FW VERSIONS!
Solange Du also eine FW nutzt, die bekannt ist, sollte auch bei "alles deinstallieren" nichts schlimmes passieren.