Steam installs to the following folder by default:
Files for games installed on Steam are stored in the following folder:
During the installation of Steam, you have the option to install Steam to a location other than the default. Since Steam relies on the game files residing in the SteamApps folder, your game files cannot be moved outside of this folder. The game files must be in the SteamApps folder in order to function.
If Steam is already installed, you may move the installation to another location, such as a different hard drive using the following process.
Please ensure that you have your Steam account name and password before following this procedure. Also ensure that your account is linked to your current email address so that you can reset your password if necessary.
It is not recommended that you install Steam to an external hard drive due to potential performance issues.
It is highly recommended that you create a backup of your SteamApps folder before attempting this process. If there is a problem in this process and you do not have a backup of your games or the SteamApps folder, it will be necessary to reinstall the games individually. Please see the Using the Steam Backup Feature topic.
The following instructions are a simple way to move your Steam installation along with your games:
Steam will briefly update and then you will be logged into your account. For installed games, verify your game cache files and you will be ready to play. All future game content will be downloaded to the new folder (D:\Games\Steam\SteamApps\ in this example)
If you encounter any errors during the move process or when Steam is launched from the new location, it may be necessary to perform a more thorough process:
If you are moving your Steam installation to a new hard drive and want to keep game saves/profiles for third party games that are not saved on Steam Cloud most of these can be found in your Documents folder: ~\Documents\[username]\My Games\. Moving this folder to the same location on your new hard drive will maintain your saves/profiles.