1. Close Cubase

2. Click on Start>Control Panel in Windows, then choose Folder Options. In Folder Options, click the View tab and choose "Show Hidden Files and Folders". Click OK to confirm.

3.

Vista:
Go to C:>Users>~your username~>AppData>Roaming>Steinberg>Cubase and delete the file called "mediabay"

XP:
Go to C:>Documents and Settings>~your username~>Application Data>Steinberg>Cubase and delete the file called "mediabay"

4. Relaunch Cubase