green screen problem

[Srinidhi s]

when i turn on my laptop the background colour black,will be displayed in green
and when ever how ever i change my dedktop image it display green in behalf of black
but other colours and things are good
black turned into green why whats the problem
how to fix it

 

[ffg7]

does this in all modes including safemode & vga mode? how long has this been going on?