We have a few servers on completely different networks and different hardware that are displaying similer problems.
When they have there external USB hard disk's connected (backup drives). A user cannot connect to them through terminal services / remote desktop (they are all running in administrator mode, not in terminal server mode).
The connection will connet and show blue / grey screen and stay there. If the USB HDD is turned off or removed the login prompt will appear within a second or two and you can now login.
Any help appriciated