Can anyone help? I have a dell dimension 1501 laptop which boots fine, but within about four or five minutes a blue rectangle appears in the centre of the screen with rows of small vertical white lines covering the screen. It then shuts down and restarts. I cannot keep the machine open long enough to virus scan, remove files I need to save, or change any settings through Control panel.

I have been reading a great deal about this type of problem, and have run the system and hardware diagnostics, which ran fine. Problem not related to power supply or over-heating. I have two batteries for the machine, both of which are holding good charge.

At the time it first happened on Sunday, I got a flashed message of "Threat Discovered" in my AVG software. It offered me the choice to heal, which I accepted. It began immediately after selecting "Heal".

Starting in Safe Mode the problem happens just the same.

I have de-selected the "Automatic shotdown at system failure" in the system settings. MAkes no difference. I have so many work files on the machinr that a clean re-install is not an option at the moment.

One option if you want to recover and back up your files before you try and fix this problem is to follow the instructions on this blog.

Yet Another Technology Site: How to recover your Windows files