i write in the form of question answers which may help you with your problems

Question
QUESTION: please help hi i have my xbox and pc hooked up to my monitor. first of all it is hd. second so when i hooked it up i figured i had hd, but i didn't after a trip to my uncles and seeing him setup his xbox for hd but on a tv i saw what i had to do and when i try to do what he did it says i need componet to be hd, but i also know that vga which is what i use supports hd, so whats my problem. to try and help i'll describe my setup

i have a pelican cooling thing on my xbox with inputs to connect things rca/etc but i had the same problem with just a regular xbox to vga cable setup. so xbox and pc to vga ab box to switch the signal whenever i want then straight to my monitor.
please help

ANSWER: The VGA should brodcast in HD but you may need to play with some settings on your xbox.  You're able to pick resolutions and such under the xbox settings menu.  Try changing the settings and see if that helps.

---------- FOLLOW-UP ----------

QUESTION: hi yes i did do that but it says i can only get hd with a componet cable.

Answer
Then you need to check the resolution with your monitor.  It may have a refresh rate or a resolution that's not compatible with the 360.  Overall, the picture will be better than standard definition on a flatscreen monitor, but not all of them have resolutions in the "HD" category, and some have some odd resolutions that might not work.