File and directory names with Windows 3.1
install-us FAQ

"I have build an installation for both 16- and 32-bit (with automatic detection). But after installing the software on Windows 3.1, the file and directory names become altered. What am I doing wrong?"

Answer: When installing under Windows 3.1 (16-bit), the system's restrictions must be adhered to. This implies that only file and directory names with eight characters are allowed: e.g. "abcdefhi.123"