Howdy!
Green lines = nice rig!
Seriously, it is all to do with your SLI set up on your cards and means you have "show GPU load balancing" ticked in the properties.
To switch it off, right click on desktop, go to properties, go to the settings tab. Then click advanced and go to the Geforce XXXX tab. In here go to SLI multi-GPU and it is the second option. Untick it and your green lines will dissapear
I had same problem for my new Alienware Rig
P.S this won't disable SLI as you want to keep it on as better performance (so make sure the "Enable SLI multi-GPU" is kept ticked!)