Download the PB setup tool according to your OS and update following the prompts.

http://www.evenbalance.com/pbsetup.php


Punkbuster A Kicks

Your firewall may not allow punkbuster to comm with the pb server.

Go to Control Panel\System and Security\Windows Firewall and select Advanced Settings.

1. Open windows firewall
2. click advanced settings( on the left) and then inbound (also left)
3. Find PnkbstrA.exe and PnkbstrB.exe (if you have two of both, its fine)
4. right click on each of them>properties>programs and services
5. make sure that "all programs that meet the specifications" is checked
6. then go to the "Advanced" tab and check all 3 boxes. Domain, Private and Public.
7. Save. You may need to update pb files again afterwards

Here's a link that will explain a few things even if its in Russian. Also included is a video. Thanks Shule.
https://www.codturkiye.net/forum/call-of-duty-united-offensive-punkbuster-add-agame-sorunu-t1303.0.html

https://www.youtube.com/watch?v=zBxsPVxmaco