There are a few things you can do to make Diablo 2 run smoother:
1. Update your video drivers. This can help improve performance and stability.
2. Make sure your computer meets the minimum system requirements for the game.
3. Close any programs that you are not using while playing the game.
4. Try running the game in compatibility mode.
5. If you are using an older computer, you may want to try lowering the game's resolution and graphics settings.