Your main drive is almost full? Consider moving some of your Steam games to other Local Disk or an external hard drive.
Steam does allow you to move games between drives easily without redownloading or reinstalling the games. This process is also faster than a traditional backup & restore method.
1. Go to Steam > Settings.

2. On the Downloads menu, click Steam Library Folders.

3. Add Library Folder and Select a new directory for Steam games.

4. Right-click on the game you want to move, select Properties.

5. Go to Local Files > Move Install Folder…

6. Select the new directory, then hit Move Folder.

7. Click Close when done.

8. Try to Play the game to see if it has been moved correctly.

In most cases, the game will run smoothly without any issue. The game save data will also be preserved, so you don’t miss your progress.