This could be your situation: you've been using Windows XP as your OS for some time and you're now debating whether to switch over to Windows Vista. All well and good, but what if you install Vista, copy most of your files over, try it out and then discover you don't like the layout or filing system, or maybe you're annoyed that too many programs need patches to be Vista compatible? So you want to swap back to XP but you're not sure how to go about it without messing up your PC for good...

This is where the latest version of System Commander comes to the fore. Quite simply, it enables you to safely partition, install and run multiple operating systems on one computer. That way you don't even have the tiresome task of transferring files and software from one PC to another or via an external hard drive.

All you do is install the supplied disc (it takes up a mere 24MB of space) and then reboot the computer and a screen will come up detailing every operating system on your PC. Whenever you choose to add another one, the program then prepares the disk to receive it and creates a new partition whilst still protecting all the data on your current OS. That way you can rest assured that whatever your feelings are about the new OS, you can run back to your old, familiar one with a swift reboot.

Every operating system created for a PC is covered, including Windows 95, 98, Me, NT, 2000, XP, 2003 and Vista as well as older systems such as OS/2, DOS, even CP/M. Linux, Unix and Solaris are also covered and booting can be done via diskettes, CDs, DVDs and even from USB devices if the BIOS supports USB booting.

If, once you've installed the new OS, you then decide you either want to remove it entirely or just certain parts, then the BackStep Wizard reveals all the actions the OS Wizard has performed along with any partitioning work, and you can quickly highlight and undo all the operations you want to reverse.

At any time one drive can be copied to another and then you can manually control such operations as Resize, Copy, Move, Create, Format, Delete and Convert. All OSs will run at full speed all the time and every OS will have 100 percent access to all hardware connected to your computer.

This latest version of System Commander has obviously been timed to deal with the arrival of Vista and to that end not only is there an automatic boot detection of Vista but there's also an updated Boot-Fixer to repair Vista's new boot process as a new OS is added to your PC, plus Vista's text-based Boot Manager can be disabled to give direct access to OSs.

If you want to alter or upgrade your OS to just about any operating system thrown at the PC since 1986, this must be one of the most stress-free, safe and uncomplicated ways to achieve it.