Priyanga06,

* Turn off the monitor
* Unplug the monitor from the computer, TV, Xbox, etc. (ALL cables)
* Unplug the monitor power cable from the rear of the monitor
* Press and hold the monitor power button in for 3 seconds
* Plug the monitor power cord directly into the wall socket. Plug the other end into the monitor
* Reconnect only the HDMI cable to the monitor and the other end to the Xbox
* Power on the Xbox
* Power on the monitor
* Press the Monitor Input Source Select button and choose HDMI

What HDMI options do you see on the Xbox?

Thanks Chris!

I will try it and let you know what happens

Just as an update, I tried using a different HDMI cable then a new xbox (I swapped mine saying there might be a problem with xbox graphics) and I still don't get HD quality.

So it is the monitor and I will try what Chris M said. 

For the options in the xbox I get; (bold ones are my current settings)

*HDTV Setting - 480p, 720p, 1080i, 1080p

*Reference Levels - Standard, Intermediate, Expanded (Tried all of them and they don't make much of a difference)

*HDMI Color Space - Auto, Source, RGB, YCbCr709, YCbCr601 (I used the current one as it says that the typical setting for HD and that's the one I used when I did get HD quality for a while)

Thanks again

Still get the same message your display indicates that this resolution is not supported at 50hz under that setting

Ok I have done what you said Chris and I get the following message "your display indicates that this resolution is not supported at 50hz" when I try to change the HDTV settings

Maybe the HDMI does not support 60Hz or I have to change the 50Hz to 60Hz in the xbox 360

Thing is you can't change the refresh rate with HDMI but I connected using composite and changed the rate to 60 and the when connected using the HDMI I still got the same message

Under HDMI Color Space, set it to Auto.

Why would you ever choose anything other than 60Hz?

What do you mean? 

I can't choose anything. I can only choose between 60Hz and 50Hz when I connect through component or composite. 

So I chose 60 and then connected the HDMI cable and when I tried the 1080p it gives me that message saying the display doesn't support the resolution at 50Hz.

I am pretty sure that the monitor is 60Hz

I am really confused

You are using the Xbox Elite with an HDMI to HDMI cable?

There should be no other input cables connected to the monitor except for the cable connected to the Xbox.

We just tested the Xbox 360 Elite (HDMI to HDMI) to 2709w. It detected automatically and the color space was RGB.

We cannot figure out you got YPbPr with HDMI? We need your step by step instructions to obtain YPbPr as we do not see this option?

Yes I am using HDMI to HDMI cable

I got YPbPr because I had the color space set to YCbCr709 but with RGB color space, I get RGB as the input color format but I cannot change it

Were you able to set the resolution to 1080p or 720p or any other given resolutions under HDTV settings? 

When I select any of those resolutions, It tells me that the resolutions are not supported by my display at 50Hz

A Vga cable is not HDMI and doesnt support 1080P

What Brand and Model TV?

What brand and model Cable?

http://www.xbox.com/en-US/hardware/x/xbox360hdmiavcable/