A recent update to PB is causing problems for lots of gamers. In order to stop some methods of getting around the PB anti-cheat they now require you are logged into Windows XP/2K with an administrator account. For users of XP Professional this is not a problem, you can either login using an admin account and play like normal, or while logged in with a limited user account you can setup the game to run under another account that has admin privileges. The problem arises with XP Home users who seem to be unable to play on PB protected servers, regardless of their settings.

Related links:
- http://www.evenbalance.com/index.php?page=faq-cod.php
- http://www.punksbusted.com/forums/index.php?showtopic=8676
- http://www.punksbusted.com/forums/index.php?showtopic=8395

** update ***
There is a fix available, for more information follow the link below. Do not follow this guide if you are not happy with making advanced changes in Windows, you will get no support from GameSlave or PB should you screw up your computer. I have heard 1st hand that this fix works when followed correctly.
http://www.punksbusted.com/forums/index.php?showtopic=8751&#entry76486