Try disabling your onboard audio / Realtek audio device in your BIOS and install a different sound card. This is not a fix, but a workaround till Dice patches this bug laden game. Also put all your graphics settings on low and increase them gradually till your system is stable.
In your settings.ini file found in the MyDocuments/BFBC2 folder, try setting DxVersion=9 instead of auto. Multiplayer is the bigger part of this game, so no way could I recommend someone go and pay 50 dollars or more for it. Single player was fun, but extremely short. Personally I don’t think this game is worth even 20 dollars, until Dice fixes all the bugs.
Unfortunately as of this time I cannot recommend this game on the PC. This has been a very frustrating game for me and for a few others that have posted here.