You can try to force it to play at a higher resolution, but success is not guaranteed.
Read this thread:
http://www.modthesims2.com/showthread.php?t=47559The thread is outdated. If you choose to do this, remember that you should look for the file under the latest EP that you have. So if you have OFB, you'd find it at C:\Program Files\EA GAMES\The Sims 2 Open For Business\TSData\Res\Config