When is a Windows PC not a Windows PC? When you toss out the Windows and replace it with Apple’s Mac OS X Snow Leopard or any other major operating system.

That’s what you can do, at least for the moment, with Rebel EFI from Psystar. The $50 (£30) application suite allows standard PC boxes with Intel Core 2 Duo, Core 2 Quad, Core i7 or Xeon Nehalem processors to install and run multiple operating systems. This capability had been built into Psystar’s computers in the past, but now the software that enables it is available as a standalone, user installable product.

The road isn’t clear for Rebel EFI, however, as Psystar is embroiled in an ongoing legal tussle with Apple over Psystar’s virtualisation technology. Until a court rules otherwise, however, you can download a free demo version of the Rebel EFI suite, limited to two hours of run time, from Psystar’s website so you can be sure that the software will work with your hardware.

Once the download is burned to a CD, you can boot your PC with Rebel EFI and then proceed to install Mac OS X Snow Leopard or any other major operating system using standard installation discs. Rebel EFI scans the connected hardware and automatically downloads and installs any necessary drivers, according to Psystar.

Psystar’s Darwin Universal Boot Loader, included with Rebel EFI, is the core utility which allows PC hardware to load multiple operating systems, including Windows 7, Mac OS X and the various iterations of Linux. The demo version can be upgraded to the full version by purchasing a registration code. Psystar also announced a new Psystar Labs approval initiative under which users having trouble with Rebel EFI and their computer hardware can have the devices analysed.