new computer not working... no idea why

Okay, i just got everything in, all the wires are in... no wires left... (checked manual so many times) then i plug in the power the monitor the mouse and the keyboard
i turn the power on! moment of suspense (beeping noise from comp)
DAM IT
monitor is showing no video input?

no idea why.. i checked video card over and over again it's in securely .... x700 256 mb memory.. help... ( and it's in the right slot)

If you're getting repeating beeps then it's most likely a memory problem. Try booting up with only one stick of memory, check each of them and make sure they work.