1. Install Virtual PC 2007 from tinyurl.com/5pgq9q. Officially, the program is supported only by XP Pro and the Enterprise, Ultimate and Business versions of Vista. If you try installing it under XP or Vista Home you'll get a warning message. Don't panic: it'll still work. Click ok to continue.

2. Launch the program and the main console and a New Virtual U Machine Wizard will appear. Since, as yet, no virtual machines exist, creating a new one is the only option available. If you're running the Home version of XP or Vista, you'll once again be warned that your OS isn't supported - just click ok.

3. Click Next to progress to the Options window, then select U 'Create a Virtual Machine' and click Next again. You'll need to enter a name for your virtual machine - a sensible option would be the name of the OS that you intend to install in it, but choose what you like provided it's easy to remember. Click Next.

4. Select the OS you intend to install from the drop down menu, U Click Next and, when the menu appears, you'll see a list of supported guest operating systems. If yours isn't in the list select Other. Most OSes that run on PC hardware can be installed under Virtual PC 2007, with the notable exception of Apple Mac OS,

5. Virtual PC will now calculate how much virtual memory U and how large a virtual hard disk your guest OS will require, then give you the option to increase that amount of memory. Unless you've a good reason to do otherwise, select 'Using the recommended RAM' before clicking Next.

6. A Under Virtual Hard Disk Options', select 'A new virtual hard disk' Wand click Next. You must now either accept the default virtual hard-disk capacity offered, or allocate more space to the apps you're going to use and the amount of data you anticipate storing. Make your selection accordingly and click Next, then Finish.

7. Insert the CD for the OS you'll be installing. When the Windows installation automatically starts up on your usual PC, end the process, On the Virtual PC console, which will now show your new virtual machine, click Start. The virtual machine will start up and the boot sequence menu will appear,

8. The virtual machine will try (but fail) to boot. In the CD menu 1:1 select 'Use Physical Drive X (X being your drive letter), then select Reset in the Action menu to cause a ,reboot. The virtual machine will reboot from disc. Follow the onscreen ins,tructions to install the OS on your virtual machine.