Are you running Zone Labs Firewall?

[Gh0st Face Killah]

If you're running Zone Labs Firewall, be warned that their latest update removes the joy of CS from your life. Version 45_530 will cause Counter-Strike to freeze up when launching an online game, so if you're planning on updating - beware

[Salvatore Buttafacio]

ive got that version .... cs works fine :blink:

[TeaLeaf]

I have that version too (4.5.53 ZAPro) and it runs steam just fine and dandy

TL.

[dead]

I had a similar problem with ZA free edition a week or so ago; the problem was, steam <%^&%$^$%%^> downloaded yet another new launcher, which ZA didn't know about, so it asked permission.  Of course, I run CS in full screen - so the ZA pop-up couldn't be moused, which caused me no end of reboots.

Solution:  Stupid, stupid, stupid me.  Shutdown ZA, fire up CS in anybody's server, change options to *run in window* (that was the stupid part), shut down, restart ZA, restart CS, then answer the ZA dialog box appropriately...  then change back to full screen death mode....

Of course, during the few moments you have ZA down, i'll completely probe your computer for all financial statements and naughty jpegs....    

[Sn00ks]

If ZA prompts you once about a program it'll place it in the programs list. From there you can set it to allow access.  

[smilodon]

The problem with ZA (and most other decent firewalls) is that in order to make sure the application hasn't been hijacked or changed by a malicous code they use a method of creating and checking MD5 signatures of applications.

Basically, an MD5 signature is a checksum of the application's executable. When the application is first run (or when the application first tries to communicate via the Internet) the Firewall displays a dialog, in which a user can permit or deny such communication. If the communication is permitted by the user the Firewall creates an MD5 signature for the application. This signature is checked during each subsequent attempt of the application to communicate over the Internet. If the application's executable is changed (e.g. it is infected by a virus or it is replaced by another program) the Firewall denies communication for this application, displays a warning and asks if such a change should be accepted (e.g. in case of the application upgrade) or not.

Every time Steam updates the executable the Firewalls MD5 signature will no longer match the new Steam executable and you will get this warning dialog. So now you know