no start

Good Morning Everyone
i have just installed a asus p4se motherboard with a intel 1.7 gig cpu and a sparkle 5300 series agp 4x card which is a nvidia tnt2 m64
when i booted it up i configured the bios to read cpu saved it It booted up alright went through post and and went into win98 boot up I then typed in fdisk to redo hard drive pressed enter and then screen went blank I soft booted it up again and still nothing could this be a cpu problem video card prob or motherboard prob being that the video card and motherboard are new
can anyone help out????