OS: Windows 7
Cannot create file whose filename begins with dot (period)
Steps to Repro:
1. Enable file extensions visible in shell via Folder Options;
2. Right click in any folder and select 'New Text Document';
3. Type name ".htaccess" (without quotes).
A 0-byte text file with the filename ".htaccess" is created.
Error message "You must type a filename" is displayed, and filename is not accepted.
There is genuine reason to create files whose filenames begin with a period, not least that it is a common protocol on web servers and other OSs to indicate a hidden file.
Renaming a file produces the same error, if the name is changed.