graphics card doesnt detect monitor correctly

hi
i have this big problem is that my graphics card as a problem that in almost 2 years it never did this
i never had problems with this computer
but what happend is that i use a LCD screen the resolution is use is 1768x992 and i use a Nvidia GeForce 9800 GT graphics card
what happends is that when i turn the computer on i see the screen with ALOT of lines with weird colors and i thought this was a drivers problem so i installed the graphics card drive and clean the PC up for the 2nd time nothing worked so i tried formating it but i doubt it that would work because those lines where there so yea
i did manage on getting a screen cap from the windows and it looks like this :

http://i954.photobucket.com/albums/a...9418/wtf-4.png


the weird part is that the lines and stuff that appear on the screen as well dont show up on the picture so i tried using another monitor and it had the same result
im using Windows Ultimate 32 bit
i have my graphics card connected to my TV(LCD) with a HDMI cable
i thought it could be that so i tried another cable it didnt work
so at this point i ran out of ideas
so i was wondering if you guys could help me
i really need my pc on my other drive i have stuff from work and i cant lose it for the life of me without counting the school stuff
please help me

I don't know how this happened to you, but the picture is very typical for a desktop that's set to use only 16 colors.

Nowadays, videocards can render millions of colors with a 24-bit or 32-bit depth, this is called "True Color." Many moons ago, you had to make do with about 65 thousand colors (16-bit depth or "High Color"), and earlier still you only had 16 colors or 256 colors (8-bit depth) available.
Using such limited color palettes resulted in images such as the one you have on your screen now.

You should be able to go into your advanced videocard settings and change the color depth, but it would be extremely unusual for a modern nVidia card to offer only 16/256 colors. Still, can you check and see which color depths are actually available?