Instructions
Verify that your emulator is capable of loading GameShark cheats. You can find this out by consulting help files or checking the developer's website. As a last resort, you can search Google for answers. If your emulator supports GameShark cheats, this information should be readily available.
Find the cheat-manager dialog for your emulator. You can usually find this on the "Cheats" or "Options" menu. If you have trouble finding this tool, check your emulator's website for more information.
Check and see if you need to enter your game's "master code." This is a special code used with GameShark devices to unlock further cheat codes. You can find the specific code for your game on cheat websites such as Super Cheats or GameFAQs. Some emulators, such as Visual Boy Advance, do not require this code. If you cannot find information about the master code relating to your emulator, assume you do not need it.
Enter your cheat code(s) into your emulator's cheat manager tool to activate them. If you have trouble getting them to work, try the master code or consult your emulator's documentation for more information.