Hrm? What appears to be the problem? I'm don't really know alot about debugging steam as I've had no problems, but here are some suggestions.
-Wipe it off, clear reg entries and reinstall.
-Turn off firewalls (XP has a native one), but wait. I have a firewall and have no problems. Hmmm.
-Decativate programs that prevent other programs from accessing the net.
Can't play games or access movies
-Sorry the Steam beta is over. No more content is accessible till they reset. No one can access it.