By default, Steam installs to
C:\Program Files\SteamAll the games you have purchased/downloaded via Steam can be found in:
C:\Program Files\Steam\steamapps\Before we proceed with the tutorial, copy and backup the "steamapps" folder somewhere safe and make sure you're logged out of Steam.
1. Once you've done that, delete all the files in your Steam directory apart from the steamapps folder and the steam.exe file.
2. Cut and paste the Steam folder to the new drive.
3. Run the steam.exe file and you can see that steam will now update itself, downloading all the required files and updating the registries.
All the future games you download will be automatically downloaded to the new drive. (NewDrive:\Steam\steamapps\GAME)
I'm currently developing a tool that automatically does this for you.
~Arcane.cfg.