Simply enter the NVidia Control Panel (there should be an icon in the task bar) and you'll see a list of options on the left side. Select "Change Resolution" and then there should be a button at the bottom allowing you to create a custom resolution. You can then manually enter 1440 x 900 in the drop-down boxes shown at the top. Then for best results, close the NVidia Control Panel, right-click on the Desktop and select "Personalize", and then click "Display". Set the Windows resolution to the newly-created 1440 x 900 and make sure the DPI setting is 100% (it may be higher by default after installing the Boot Camp drivers). You'll need to log out for the new settings to take effect.