Help With Odd Computer Problem

[bort411]

I would try turning off/configuring all firewalls you have running. I get similar problems sometimes when BF2 is starting up and my software firewall is running. This is assuming HL2 tries to communicate with the internet at some point during the boot up/login process. Even if it doesn't this is still something you can try.

[Meech]

It's crapped out on me before because of firewall issues. My firewall stores the checksums of the executables, and when it changes I have to manually re-authorize it or it flakes out.