I don't think anyone is going to take the time of the day to help you if you blatantly ignore help and not saying what you have or have not done.
TBH there is no way to go about this other then reinstalling it. Try redownloading the client or optional, try putting this in Freestyle Gunz and overwrite with this http://www.mediafire.com/?8e8b1bcnocsbfds
May or may not work, but the issue seems to be around the patch.xml file.
EDIT: Try disabling anti-virus and firewall then trying.