Graphics gone wild

[Glennmc7]

I have a very strange problem so I was hoping someone else my have a clue to what is really going on here.  My problem is that sometime not all the time lets say 5 out of 10 times when I boot up as soon as I get to the screen where you see the blue line loading Windows the screen is all lines but as soon as I get into Windows or the desktop it with display the graphics as normal like any desktop screen.  The graphics card is a 9600 GT with 512 DDR3 ram which is brand new plus a bland new 800 Watt PSU and I had ASUS replace the 9600 GT for a new a new one for just this same problem as I thought that the video card was the problem but evidently not as I still have the same problem with the new card and I have also installed the newest drives both from the CD and the NVIDIA and ASUS website with still the same problem so maybe someone else has had this problem to so please I need help I seem to be losing my hair any help. 

System

Intel Core 2 Quad 3.33 GHZ

Hard Drive  1 TB

Ram 4 Gigs DDR3

Asus motherboard

800 Watt PSU

DVD Rom

[Karnac]

Are you getting any conflicts in device manager?....... Is there another slot you can try the card in....no sources of EMI nearby,... wirelessphone or flourescent table lamps,etc.