Steam recently added a feature that lets you add additional game libraries, letting you store your games on a different drive. This is a long-sought-after feature that many would consider pretty basic, however, even though it’s now available in the client, it’s not great: it only works for games without shared content which means anything that uses the Source engine (for example) can’t be installed in any library but the primary one.

Not good enough. You’re better off using a symlink to get around it and put the entire steamapps folder on the drive of your choice.

  1. Close Steam.
  2. Go to your Steam installation folder.
    • 64-bit: C:\Program Files (x86)\Steam.
    • 32-bit: C:\Program Files\Steam.
    • If not, you should probably know where it is already.
  3. Move the steamapps folder somewhere else. For example: D:\steamapps.
  4. Open the command prompt. Either Start -> Run -> cmd.exe and navigate to the folder or hold shift when right-clicking the empty background of your Steam folder and click Open command window here.
  5. Run the following:

    mklink /D "C:\Program Files (x86)\Steam\steamapps" "D:\steamapps"
    

    Adjust the paths according to your configuration.

  6. Open Steam.