Screen jumps between desktop & metro right after login

Hi,

Right out of the blue, windows 8 loaded up painfully slow so i restarted my HP g6 laptop.
After restarting the laptop the user login screen appeared fine fine but as soon as i login the metro tile screen flashes to a default coloured desktop screen and back to to the metro screen every second. It is continous and you can't access anything as the screen jumps to the other one before you can even do anything!
My laptop is only a few months old and there has been no hardware change/upgrade.
I managed to get into the system restore and restored to a point a few days before this issue started but, when the laptop restarted, the issue remain and the screen jumped between the 2 screens.
There are no error msgs or any can of beeps that appear. There was nothing of any note that happened prior to this issue occurring and the laptop worked fine until this issue.
Tried searching google & forums regarding this issue but it doesn't seem to be a well known issue at all.

Has anyone got any idea why this is happening? Hardware or software issue? Windows 8 error or bug?
Anyone got any potential solutions? Any help would be greatly appreciated.

Thanks,

Shuja

What happens if you press I while it's happening?....almost sounds like a repeating Windows Key.