In Display Properties > Settings tab, is that Samsung monitor listed in the section called "Display"? If not, click the pull down arrow and see if it is in the list. If so, select it.
If it is already listed, click the Advanced button and explore the options there.
when i bought the display at best buy, the guy just gave me the monitor and cords, no software or nothing. When i hooked it up to my HP Media Center TV PC the display options were only 800by600 and 1024by768. I went to the samsung web site to get the driver for it. when i installed it, i still didn't get any widescren resolution options. Before i had this monitor, i had an emachine 19" widescreen. And it worked perfectly. so i know that my graphics card can handle 1440by900, i just don't understand why it doesn't work now. Help would be greatly appreciated.