As stated in Part 1 of this Mac Mini HTPS series where I evaluated different Media Center and HTPC software options my choice was to go with MediaPortal, an excellent open source and free software for turning your Windows PC into a living room digital media master. In other words, we need to load the Mac MIni with some kind of Microsoft OS software. Fortunately, the engineers at Apple has anticipated this and made this very easy to do as long as you have access to a Windows XP (or VIsta or Windows 7 beta) installation CD.
Any version is fine as MediaPortal supports more or less any post XP SP2 version Windows. Personally, I chose Windows XP SP3 as it is very stable and currently provides the best performance for the Mini hardware. Also, once the software has been installed and configured according to this guide, the OS itself will in practice be invisible anyway so there is little benefit from the nice but resource heavier Vista or Windows 7.
Software: Windows XP installation CD/DVD, Apple OS X Leopard Installation DVD (for installing Windows XP drivers for Mac Mini hardware)
Hardware: Intel Mac Mini 2nd or 3rd generation (runs well on 1.83 GHz Core Duo), a USB TV tuner supported by MediaPortal
Other: Internet connection, some patience and a couple of hours of time to spare