Thank you for all the helpful replies. There was apparently a problem with the driver supplied and my graphics card. I have downloaded a compatible driver which now enables me to set the resolution to 1920 x 1080.My pics are now in proportion and look far better on my new monitor which I am now very pleased with and would recommend to anyone wanting to replace a monitor (BenQ G2222HDL 21.5-inch Widescreen LED Back-Light Monitor £99.99 Amazon) Thanks again Rod
should be in the manual and generally the highest the graphics card will allow (as long as you have the option selected for only show resolutions supported by the monitor)