Windows 7: hdmi boot issue 720p

Hey all,

I have a small problem when trying to boot windows 7 with my hdmi out to my sony 32 inch bravia 720p. I can make it work fine by keeping a monitor hooked up and windows login screen will appear on my tv in 1080i than the monitor shuts off. I had no problems connecting to my brothers tv and booting straight with the hdmi because his lcd tv had 1080p. Anyone know something I can do so I do not have to keep the small monitor around as a workaround? Was thinking maybe set the resolution lower could help but not at home to try. Any ideas would be great.



Thanks