I have an HP laptop and when I start it up it will bring up the login screen and these black flickering lines will start on my screen from left to right all over the screen and when it gets bad the entire screen will go blue with black vertical lines they don't move or anything they are just there and I have to restart my computer and then its fine can any body give an answer as to what it is? And why it happens? I have windows 7 if that has anything to do with it

This could either be a hardware of software issue.
Before starting, make sure there are no devices connected to the laptop, i.e.. USB devices. Also remove CDs from the cd drive.
Depending how old you laptop is it might not have some of the features I'm about to talk about.

--First check hardware--

1 - Once in windows run a diagnostics test. Click Start , All Programs , PC Help & Tools , and Hardware Diagnostic Tools.
2 - Turn the laptop off. Now switch it on and wait for the HP logo to appear. Once there, press the "F11" key multiple times till your laptop entered HP's Recovery Menu. Once there, click the Advanced button on the bottom of the screen then tic the box "Computer Check up" and click next.
3 - Replace any hardware if faulty.

--Software Issue--

1 - Might be a driver issue. Update drivers.
2 - Might be some software conflicting with the graphics card. I once had a problem with the Bluetooth software BlueSoleil. It change my resolution every time I restarted.


Hope this helps
Grant Hills
South Africa