Colin,

Depending on the video card you have, this may or may not help you. I have an nVidia card...

In Vista right click on the desktop, go to personalize, click the display settings link, click advanced settings button, click GeForce tab, click "start the NVIDIA control panel", on left side you will see under the "display" menu tree: "rotate display", click that and then adjust as needed.

If you have an ATI video card, you should have a similar control panel setting, just hidden somewhere else.

Hope that helps.

-Joe