Many Tablet PCs are still shipping with Windows XP Tablet Edition. Luckily, Speed School provides a copy of Windows Vista Ultimate Upgrade as part of the software bundle. If it saves money and you are willing to put up with the headache of installing another OS, it is a possible option. However, it still may not be the best option.

It may not be worth going with a downgraded version of Windows simply because it will mean you have one less copy of Windows Vista to install on a computer. For example, if you have a desktop or another laptop, you may want to use your extra copy of Vista on that computer.

Vista is able to switch between versions by simply changing the product code. This means you can upgrade from Vista Business to Vista Ultimate by only typing in a 25 digit code (in theory). Also, downgrades should work in the same fashion between different versions of Vista.

To keep things as simple as possible it may be best to just purchase a Tablet PC with Vista. This guarantees things will work, and if you want to upgrade to Ultimate later it is always an option.

From my personal experience, there isn't enough insentive to get the Ultimate version over another version. There are limitations, but for most users they will never run into them.