I saw somewhere that in Windows 7 you should go to the file location and click on launcher and "select the correct size of your screen resolution". There are 3 options: 800x600, 1024x768, and 1280x1024. My screen resolution is 1920x1080. I am hesitant to change it to match one of the game options as I don't know how it will affect my computer.
I'd choose the largest resolution it allows.
Does your monitor have a scaling option? Does it allow you to have black bars on the sides, or a black frame around the picture?
If not, see if your video card has a scaling option.
Usually the worst thing that happens is the game crashes and leaves your desktop at a low resolution (and your icons all messed up). Usually a reboot fixes it, but sometimes you have to manually go in and change your desktop resolution back to what it's supposed to be.
(Right-click the desktop --> Personalize --> Display --> Change display settings --> Use the dropdown box to select the resolution you want and save changes.)