The operating system (OS) for your computer is an important choice, as it not only determines what software you can run, but also affects the price quite considerably.

The standard OS for the SpaceCube is WindowsXP Home edition (with latest service pack), which is the most recent release of Windows. It runs a vast array of programs, and because of its pedigree (WinNT and Win2000 rather than Win95/98) it is a secure, robust operating system, with good networking capability.

WindowsXP Professional offers more security, encryption and high-end networking facilities for business/corporate users. For home users, it offers little benefit, apart from supporting Remote Desktop, a feature which allows you to drive the machine from a different machine. This functionality is similar to the Remote Control software bundled with all SpaceCubes, and Remote Control has special support for this too. However, whether it is really worth the extra for most users is hard to say.

Windows98 is an older operating system, and arguably less stable/reliable. It is favoured by gamers and those who prefer its more no-nonsense approach - ie. fewer wizards, pop-up help etc. In all honesty, you shouldn't select this option unless you know in advance that you want it.

Linux is available as an option for those who wish to avoid Microsoft. Doing so will close many doors software-wise, but there are many who want to have their SpaceCube Linux-ified. You may be surprised by the cost difference between Linux and no operating system. The reason for there being a big difference is that Linux takes time to install, and this has to be factored into the price.

Finally, if you already have an operating system, or want the "fun" of installing everything yourself, you can save yourself a fair amount of money by choosing not to have an operating system.