I have mediawiki installed, and I have xampp.

I have this in my mod_rewrite (or whatever you call it)

RewriteEngine on
RewriteRule ^/(.*)/index.php/Special:Userlogin(.*) https://%{SERVER_NAME}/$1/index.php/Special:Userlogin$2 [L,R]
RewriteCond %{QUERY_STRING} ^title=Special:Userlogin
RewriteRule ^/(.*)/index.php https://%{SERVER_NAME}/$1/index.php?%{QUERY_STRING} [L,R]


it works perfectly so when you are directed to login it goes to https://www.mywerbsite.com/wiki/login/ (or whatever)

Once it is logged in i want it to switch to http://, but it stays in https://.

any help would be greatful.

Check wiki config file. Probably a settling that you can edit that let you surf via http:// mode.