- Please be sure that you are running windows with a user account that has Administrative privileges.
- If using IE please add http://quakelive.com to the trusted zone by double clicking at the bottom of the window edge where it says 'protected mode' and also untcking the " Require server verification (https: ) for all sites in this zone" box
- Clear your browsers cookies/cache
- Try the site again
Once the above steps have been completed, if this still fails, locate your baseq3 directory which contains the .pk3 files and remove it (it should be at the same level as the /home/ directory covered in this post , the game will recreate this directory and re-download the files with correct permissions when you log in again.