Why can't I change my screen resolution?

I know how to but it's stuck at 800x600. It won't let me change it so it's smaller and it's so annoying.Why can't I change my screen resolution?
Usually that is caused by the type of monitor that is defined/installed within the Device Manager. You can try changing that to a different one.Why can't I change my screen resolution?
you might not have a graphics card capable of smaller resolutions, or the appropriate driver for it. check out windows update, and select custom updates. they may have the updated driver for your card.
Try removeing it from your device manager then rebooting, it should set up everything from scratch. You can then re-install the drives with your CD or go to the website for the latest drivers. If that does not work then the last guy is probably correct about the capabilities of your video card.