Fixed it
To fix this:
1) Open a Remote Desktop session to the server. You don't have to log in with the Administrator account, but you should use an account with admin access to the server.
2) Click Start, Control Panel, Administritative Tools, Terminal Services Configuration
3) In the right panel, click on 'Connections'
4) In the left panel, right click on 'RDP-Tcp' and select 'Properties' from the right-click menu
5) Click on the 'Sessions' tab
6) Check the first checkbox ('Override user settings - End a disconnected session:')
7) Select '1 minute' from the dropdown list. You can use a longer interval if you wish, but it
should be reasonable finite length. This will dictate how long you have to wait between
WHS Console sessions.
8) Click okay. Click okay to any messages that appear.
The above changes will not affect any existing sessions, so you will need to manually kill any
existing disconnected sessions:
1) Right-click on the taskbar, and select 'Task Manager' from the right-click menu
2) Click on the 'Users' tab.
3) The existing sessions will be listed on this tab. For each session that says 'Disconnected' in
the 'Status' column, select that session and click the 'Logoff' button.
4) Click yes to confirm, and close the Task Manager
5) Log off of the server.