If you are looking to rename a file like htaccess.txt to .htaccess and you are stumped because when you attempt to right click and “rename” you get a “You must type a file name” error, below is what you can do.
Go to Start -> Run -> cmd.
Once inside command prompt navigate to the folder there you htaccess.txt file is located. Once there, type the following into your command prompt:
rename htaccess.txt .htaccess
Voila, your htaccess.txt file has been renamed to .htaccess!