If you want to increase your arsenal of weapons to include the following then complete the indicated task to get them.
Visit the website findallfive.com and select the 'Join the Battlefield Community' option and sign up with Electronic Arts. When you then register for the 'Battlefield: Bad Company e-mail newsletter' you will receive a unique code by e-mail which will enable you to unlock this destructive weapon.
Unlock F2000 Assault Rifle:
Register your old Battlefield games at http://www.veteran.battlefield.com/
Unlock QBU-88 Sniper Rifle:
Unlocked through a unique code which was provided if the game was pre-ordered before June 23rd, 2008.
Download the 'Battlefield: Bad Company' demo version and then select the 'Quick Match' option. Then play a ranked match and get over 23,000 EXP to reach Rank 4.
Unlock USAS-12 Semi-Automatic Shotgun:
When you view your multiplayer stats online this weapon will be available the next time you sign into the game.