anguslai,
You will need to leave some more information if you want someone to help.
Which skin are you using?
Posting the "System Information" report text from WindowBlinds 5 configuration panel is also requested.
Can you open the Start Menu with the "Win-Key" on your keyboard? If so, this would suggest a problem with the skin, the graphics adapter (or drivers) on your machine, or a bad installation of WB5.