It’s cool that most OSes, filesystems and apps provide at least certain level of support for non-ASCII characters. Too bad that in a lot of cases they don’t work too well, especially when mixed together. That’s why it’s usually a good idea to stick strictly with ASCII-only characters. I’m afraid you can’t prohibit such files from being created but you can occasionally mass rename them afterwards.
For most European countries the character set is usually just a small amount of extra characters over the plain ASCII set. For these and similar cases I’m gonna provide a fairly simple method to enforce ASCII file and folder names on your system.
Start it and navigate to root folder which you want to contain ASCII-only names.
Check Subfolders on the middle bottom and wait for the list to be populated.
Go to Options / Character translations and provide your non-ASCII -> ASCII conversion options. For Hungarian it’s:
á=a é=e í=i ó=o ö=o ő=o ú=u ü=u ű=u Á=A É=E Í=I Ó=O Ö=O Ő=O Ú=U Ü=U Ű=U
Click somewhere in the file list and press Ctrl + A.
Wait for the renaming to finish. Done.