what could be the problem!

[rajpootr24]

i have dell precision m6600 with amd firepro m8900
from last two weaks when i start my laptop everythings good
when windows appear on screen (where i have to put my password) . it shows a lot horizontal blank lines when i enter my password suddenly a black or blue screen appears , now i am using safe mode>
what could be the problem??
is it my graphic card malfunctioning or windows error?

 

[webworkings]

So it works fine in "Safe Mode"? When the screen was showing black/blue was the cursor on the screen?

 

[hang-the-9]

Are you actually running in Safe Mode or is your graphics just at a low resolution? A lot of times people say they are running in Save Mode when the only thing that is happening is that their resolution and/or other video settings are not set properly. From your image issues, seems like the video card is failing.