I cant update the guide right now, but i'd like to add a part about PAL users. Also For enabling 480p blindly.
If you have a PAL xbox, you'll need to switch your xbox to NTSC by using a mod chip or enigmas video mode switcher. Note, I DO NOT HAVE A PAL XBOX so i take no responsability for things going wrong. I have not tried any of this switching, but others have tried these methods. PAL xbox's have HD modes disabled, and you can only enable them with NTSC xbox's.
Once you do that, or even if you have a NTSC xbox, you'll need to enable 480p. To do this without having another component cable, you'll need to hook up your VGA adapter, then enable the 480p blindly as follows:
When at the MS dashboard do this:
Down 5 times, Hit A
Down 3 times, Hit A
Down 1 time, Hit A
Left 1 time, Hit A
Hit B 3 times to go back to main menu.
Reboot
After you do this, you should be able to connect the cable to the PC monitor and it should work great.