My Windows 8 Laptop was displaying a flashing purple screen alternating with the desktop.
Could not access internet.
Rebooted in safe mode, with networking.
Downloaded and ran Spybot and Malwarebytes.
Did not solve the problem.
Eventually (following a google search) uninstalled Norton 360.
Solved the problem immediately.
So right now I have no virus protection.
Is there a solution to this Norton 360/Windows 8 problem?