desktop xps 8100 don't start windows

there's no dell logo in boot, but its "normal" here, never was anything in starts,

after clicking power button, screens stays black, then shows only "welcome" from windows...

but now, i press power button, hdd seams to working, or doing something...

i have network here, the computer even with no screen doesnt show in network, so i think its not gpu

i tried to shut down with no screen, only using keyboard, to know even if no screen, windows could be "behind" this no screen

monitor is ok, i got 2 plugged in a nvidia 240, booth stays in stand by

i tried to plug out all usb devices, no keyboard or mouse, then tried only within mouse and keyboard... no sucess

no cd/dvd/bluray in... no beeps, no sounds of error.... so weird

any help? thanks!