I receive the error message "Your account <account name> is currently in use at another machine. You'll need to shut down Steam on your other computer in order to log in here." What should I do?
This error indicates that another computer has recently been logged in to this Steam account. A Steam account can only be logged in from one computer at a time. Rapidly switching the account between multiple computers may result in a temporary lockout.
If you repeatedly see this message, please restart your computer and re-test the issue. Make sure to try launching Steam.exe directly from C:\Program Files\Steam\ (or your default Steam directory) to further test the issue.
If the issue persists, please Contact Steam Billing and Support