when i start up my computer is goes through windows then the screen goes black and says ''Cannot Display this videomode Optimum resolution 1280x 1024 60Gz i have a GForce 8800 GTBoot into Safe Mode by pressing the F8 key on your keyboard before Windows splash screen.

Once into Safe Mode...go to ControlPanel/Display/Settings Tab

Change the resolution to a lower number...try...1024x768 to see if this fixes the problem.I cant seem to get into the safe mode once the system boots up it goes to the gigabyte screen then the windows loading screen then the screen goes blue and it says setup restarting then it goes black. I made this computer and had it working before i reinstalled windows its just STARTED happening now.Try this to start in safe mode:

# Restart your computer.
# When the machine first starts again it will generally list some equipment that is installed in your machine, amount of memory, HARD drives installed etc. At this point you should gently tap the F8 key repeatedly until you are presented with a Windows XP Advanced Options menu.
# Select the option for Safe Mode using the ARROW keys.
# Then press enter on your keyboard to boot into Safe Mode.That DIDNT work either i dont even have the option of a save mode all i have is the dios menu could i do it from there? I dont get why it worked before but when i reinstalled windows and it rebooted then it just started happening i think i have to config the mother board again if that makes any sense.Had you mentioned you had re-installed Windows that would have saved some time and effort...
After any re-INSTALL of an OS the existing drivers are wiped out...
Re-install both your MBoard drivers and the video drivers and report back with the results...

P.S. The motherboard drivers should go first...Oh sorry about that, i cant get to any kind of desktop screen i dont know any other way to install a driver the only thing i can go to is the Dios screen