Q:

htaccess 301 redirect with ? ( question mark) in URL not working

This is probably a simple question, but I can not find why the 301 with an ?  in the URL is not working.  I have done a 301 redirect in the .htacces file but it´s not working.  Other 301-redirects are working except for the one with a question mark in the URL. 
I want http://www.example.com/?forum=2115543 redirected to http://www.example.com but the simple standard 301-redirect doesn´t work. 
Example in .htaccess: Redirect 301 /?forum=2115543 /

A:

You can not match a query string with Redirect (mod_alias).  You need to use mod_rewrite. 
You can give this a try. 
RewriteEngine On
RewriteCond %{QUERY_STRING} ^forum=(.+) [NC]
RewriteRule ^ /? [ R=301,L]

