New build shuts down after (windows is loading files) and says starting windows

[deathskull77]

I've tried for 3 days to install windows 7 but it doesnt let me!
i boot off the disc and it says "windows is loading files" then "starting windows" and it just shutsdown! i have to flip the PSU switch for about 5 seconds then flip it back then the computer will start

MOBO A780L BIOSTAR
CPU AMD ATHLON II X3
RAM 2X1GB DDR2
GRAPHICS CARD NVIDIA 8400GS
HDD 40GB SATA

 

[deathskull77]

PSU 480W
OPTICAL DRIVE DVD RW burner