1. Ensure your Action Replay device is compatible with your Pokémon Black game and has the latest firmware installed.
Step 2: Obtain the Mew Code
1. Look for a reliable source online for the Mew code specific to Pokémon Black. Ensure the code is compatible with your game version and region.
Step 3: Activate Cheat Codes
1. Insert your Pokémon Black game into the Nintendo DS.
2. Insert the Action Replay device into the Game Boy Advance slot of your DS.
3. Power on your DS and launch the Action Replay software.
4. Select the "Cheats" option from the Action Replay menu.
5. Enter the Mew cheat code you obtained earlier into the Action Replay device.
Step 4: Catch Mew in-Game
1. Launch your Pokémon Black game from the Action Replay menu.
2. Play the game normally until you reach the location where Mew can be found. For Pokémon Black, Mew is found in the Hall of Origin after beating the main storyline and the Champion.
3. Once you reach the Hall of Origin, encounter Mew, and enter a battle.
4. Mew will likely be at a very high level, so use your strongest team and be prepared for a challenging battle.
5. Once you defeat or capture Mew, it will be added to your in-game Pokémon collection.