Right click on your WoW folder and uncheck read-only. Afterwards, set your WoW/WTF/Config.wtf to this:
<blockquote class='code_blockquote'><dl><dt>Code: </dt><dd> </dd></dl><code>
SET realmlist "192.223.25.140:3725"
SET patchlist "localhost"
SET locale "enGB"
SET accounttype "MP"
SET realmName "Freedom"
SET installLocale "enUS"
</code></blockquote>
Lastly, try running WoW as Administrator.
<blockquote class='code_blockquote'><dl><dt>Code: </dt><dd> </dd></dl><code>
SET realmlist "192.223.25.140:3725"
SET patchlist "localhost"
SET locale "enGB"
SET accounttype "MP"
SET realmName "Freedom"
SET installLocale "enUS"
</code></blockquote>
Lastly, try running WoW as Administrator.