When I started my Windows 8 CP, I saw the start screen had nothing on it. I have to press Windows Key + D to open the desktop. I think that is blank start screen.

Any idea on how to fix it? I have tried restarting and signing off and on, but it has not been successful.

Does this mean the Metro screen is black but the Desktop is working?

Your installation sounds corrupted. You could try a Refresh or Reset.

Hope this helps.

Method 1:
I would suggest you to remove all the external devices (except mouse and keyboard), restart the system and check if the issue occurs.

Method 2:
I would suggest you to update the display drivers in Compatibility mode and check if it helps.
a) Drag the mouse to bottom left corner and right-click on the ‘Start icon’.
b) Select ‘device manager’
c) In Device Manager, locate the device you want to update, and then double-click the device name.
d) Click the ‘Driver’ tab, and then click ‘Update Driver’ and follow the instructions
Also, I would suggest you to try reducing the screen resolution from Control Panel and check if it helps.

Method 3:
To do this, follow these steps:
a) Press Windows Key +Q, type Screen Resolution in the search box.
b) Reduce the screen resolution using the slider and check if it helps.