Instructions
Download all the latest software updates for both your Xbox 360 and "Battlefield: Bad Company 2." Software updates for both your hardware and your software will improve their compatibility with one another and allow them to connect to newer, faster servers. Both of these things reduce ping. You will be prompted to download any available updates whenever you load "Xbox LIVE" from your console's menu.
Pause or stop all active downloads on your Xbox 360 dashboard. If you're downloading a game demo or downloadable content while attempting to play "Battlefield: Bad Company 2" online, your ping will naturally be higher because your bandwidth is being split in too many directions. Pause all downloads and attempt to play the game again to lower ping.
Plug your Xbox 360 directly into your modem instead of into a router. Plugging directly into the modem will not only naturally lower your ping during online gaming but it will also prevent other devices in your home from using bandwidth from the same Internet connection. When you're done playing the game, hook the Xbox 360 back into the router to resume the normal operation of your home network.
Test your Xbox 360's wireless connection. Verify that the console doesn't find any errors with the connection configuration that could be raising your ping. Open the "Network Settings" option from "My Xbox" menu and select "Test." If errors are identified, your console will tell you what you should do to fix them.