Color Quality is set on "Medium (16 bit) and it is stuck there.
Screen Resolution also stuck at 640 X 480

Tried right click
Properties
Setting
Thats where I see the Screen Resolution and color quality.
Both are set at the above settings and the slider on the screen resolution
wont slide. The drop down box on the color quality has only one option (16 bits).
The monitor is showing defult monitor. I donnt have Monitor CD. Any help will be highly appreciated.
Thanks.

   Either your monitor will not support anything else (I doubt it) or you need the correct driver for your monitor.  If you get the correct driver, it will allow you to select more.
   I would first look at the manufacturer's website of your monitor.  If you don't find anything there, try using other default drivers in Windows or do a search for drivers for your monitor on the internet.
   If you have Windows XP, it should have the correct driver.

Thanks Ray, My Monitor is Samsung SyncMaster 591s.I have downloaded the driver as suggested by you. But When i tried to install the driver, it gave the error message.

       Video card driver is not intalled properly.Please install video card driver first for      monitor auto installation.

I dont have a seperate Video and Audio card, It is onboard. My OS is Widows XP SP2 WHICH I INSTALLED RECENTLY, after which the problem started.Even my audio is not working.I read that this problem may occur when a OS is newly istalled. My mtherboard is KOBIAN PI845 GLM 5.0.
IS THERE A WAY OUT. THANKS.

   Your motherboard probably has the video card on it as a part of it.  Windows XP is supposed to have all drivers and it sounds like it doesn't or the driver that it has is not working.  Maybe your motherboard's manufacturer has drivers on its website or an answer to this problem.  I would ask them.
   A way around this, howbeit an expensive way around, would be to buy a video card and install it.

Thanks Ray, You are absolutly right. My motherboard have onboard video and audio card.Somehow the XP installation missed out/CORRUPTED  the right drivers.I installed rhe drivers with the motherboard CD-ROM.Now its working OK.
Thanks a lot.