https://bugs.winehq.org/show_bug.cgi?id=39025
--- Comment #8 from Bruno Jesus 00cpxxx@gmail.com --- It looks like you have more drives than it's possible to mount, winecfg error seems clear in saying that it is running out of letters.
Please attach the output of: WINEDEBUG=+winecfg winecfg -d &> log.txt