Windows screen on my laptop turns green and fuzzy

The basis of it going green now and then may be something to do with signal. If this is an intermitant issue with your screen then i would check the cable in the back of the LCD.. also the connection on the motherboard.
There are only 4 factors of having bad screen these are

*LCD cable - signal for picture
*Inverter - light for your lcd
*LCD Screen - to view
*GFX Card - produce signal

Hope this helps.