Q: How do I disable VAC 2?
A:
VAC 2 is a system hosted, provided and (un)supported by Valve. The server runs the Valve Anti-Cheat dll by default. If you wish to disable VAC2, all you have to do is add "-insecure" to your server's command line. As a Counter-Strike.com customer, you can do this quickly and easily like this:
1)Log into CS Admin
2)Click on Game Servers
3)Click on your server ip address
4)Click on Command Line Changer
5)Click on New
6)Fill in Command Line Name with a name such as VACDisabled
7)Under Select make sure all options are checked
8)Make sure the value for +exec says server.cfg
8)Make sure the value for +map says de_dust2 (or any map you want your server to start with)
9)Go back to Command Line Changer and click on select next to the command line you just created
10)Your server should restart automatically. If your server does not restart, select the default command line changer to set your server back to default.
11)Open a support ticket if this is unsuccessful.
www.counter-strike.com/faqs/#30