The Clear Display Key is no Longer Working
When the Clear Display key does not work, it is usually because a Notebook is open.
Whenever a Notebook is open, the Clear Display key is disabled until the Notebook is closed. The key is disabled so that you don't accidentally erase an open Notebook.
To Close a Notebook:
1. Go into the Toolbox, and select the key labeled Notebook menu.
2. Select the key labeled Close Notebook.
3. This will prompt the message, “The Notebook has changed. Would you like to save changes?” Answer, NO.
NOTE for Step 3: If you deliberately opened a Notebook and were working in it, you might want to answer YES to this question to save your work.
4. Next select OK to exit the Notebook menu.
Add some text to your display and test the Clear Display key. If the Clear Display key works properly you are finished.