in c:\xampp\apache\bin\

htpasswd.exe -c -b .htpasswd ausername apassword

htpasswd -c /home/folder/.htpasswd ausername 

and then add the following to your .htaccess

AuthName "test"
AuthType Basic
AuthUserFile "C:/folder/.htpasswd" #or "/home/folder/.htpasswd"
require valid-user
DirectoryIndex index.php