Enable/Disable NIC functionality

Platform: Windows XP Pro
Network: 10/100 Cable Router (Non-Wireless)

I have two user accounts in XP, one for games, the other for the internet.

The computer has two network cards, one devoted to the internet, the other to my home LAN.

A while ago I created a small utility which enabled and disabled either network card based upon which account I loaded.

Since the other computers don't need to browse the internet it allowed me to leave the remaining games systems unprotected without the need for a firewall.

After a while I began to notice the program begun to fail randomly or when the system was under strain. :eek:

The code I'm using enumerates through the 'right click' menu and performs the appropriate command, however if I right click at the same moment the action is cancelled.

After a while I added longer durations and it seemed to help, however I would like to know the program always works.

I could simply disable DHCP in the gaming account however I noticed packets were still being received. All though I cannot access the internet without DHCP, I was wondering if anyone could tell me why I was still receiving packets...?

I'm looking for alternate source code and any other services I can disable to make certain the internet is off whilst in the games account.

The account has full admin rights so the sky is the limit... :)

You can find an example of the code I used here, scroll down the page a bit.

http://www.vbcity.com/forums/topic.asp?tid=56821

Thanks in advance.