Quote Originally Posted by Sky Soldiers View Post
You never confirm if you did selectively boot as suggested by Guru GeorgeV here :

http://www.zonealarm.com/forums/show...036#post296036


See here also : Using the Selective Startup option, you can turn services and startup programs on or off individually to see if the problem occurs the next time you restart your computer.

http://windows.microsoft.com/en-US/w...-Configuration

Have a nice Day
I have found out the cause of the problem.

ZA 11 conflicts with AVG 2013 AV.

Despite having uninstalled AVG and ZA, then installed ZA 11 and went through the re-booting procedure, I re-installed AVG. I got the black screen again.

As I have paid for AVG, and am very satisfied therewith, I have reverted to ZA 10, and will await some fix to be installed in ZA 11 that will prevent this conflict.
Quentin