Vista - Keep losing Internet connection

I have a Dell XPS 630 system with Vista Home Premium 32 bit. I am connected to the Internet by cable modem. I like to play COD World at War online and here recently while playing online I'll get kicked for losing "map packets". I'll run windows diagnostics and get a msg "cannot communicate with primary dns server". The only way I can get back online is to reset the modem by unplugging and waiting a few minutes before plugging it back in. I disconnected my wireless system thinking it may be the router and hooked the modem directly to my PC. No such luck as the problem still occurs. I contacted my ISP (Cox) and they assured me it's not a problem of theirs. I changed cables thinking I had a bad one but it still occurs. My NIC is Nvidia nforce 10/100/1000 and the driver is up to date. Any help would be highly appreciated.

Make sure your Primary and Secondary DNS servers (in your Modem)are set up they way your ISP describes. If you have set this as "auto" you'll need to override it.

Check your Modem logs...there might be some clues there for the disconnects. This shouldn;t be happening on a cable modem.

Check your Network connection settings.... tutorials are available in the Tutorials section of this fine forum