Have you ever needed to test out a new bit of software or a new version of an operating system but didn't have a spare computer that you could allocate for the testing?

If so, the solution is simple.  Your computer can run a bit of software that will emulate a computer inside of a computer, enabling you to run Operating Systems such as Windows XP, Debian and other PC based systems.

You may already know about the computer in a computer software, but have never found a need to use a use for it.  Or perhaps you couldn't justify the expense of buying an extra bit of software that doesn't have any obvious curriculum benefits.

There are 2 mainstream contenders in the Virtual PC software market.  Each have there merits and are very user friendly.

• Microsoft Virtual PC (www.microsoft.com/virtualpc)
• VMWare Desktop (http://www.vmware.com/)

Both of the mainstream emulators have a polished GUI frontend and give you the flexibility of being able to pause a computer and put it to sleep so that you can resume your testing the following day.

VMWare has the added advantage in that it allows your USB devices attached to your host PC to be available to the Virtual OS.  So your WebCam can run on the Virtual OS where the drivers are installed, but your regular host machine doesn't need to have the drivers.

The other useful thing is that when you have the client software installed onto the Virtual OS, your mouse floats seemlessly from Window to Window and control is passed to the relevant operating system.  You can also copy and paste into the Virtual OS.

Now this is all very well, but both VMWare and Virtual PC cost money.  So you might want to consider looking at an alternative that is free.  It is called QEMU (http://fabrice.bellard.free.fr/qemu/) and is a full x86 PC emulator that will run most Operating Systems.

The downside of this software is that it is all command line based.  This makes it difficult to use and you would have to digest at least 80 pages of text before you understood all of the command options.

The good news is that you can experiment and then create a batch file that will run the virtual OS for you.  Now it would be a good idea to document your batch file so that you can remember all of the command line switches and what they do in a years time.

An example command looks like this;

qemu.exe -L . -m 128 -enable-audio -localtime -cdrom pebuilder.iso

As you can see, it isn't all that friendly.  But basically this command sets up a machine with 128Mb RAM and boots from a CD image called pebuilder.iso.  In this case I used it to test a BartPE image that I had just updated.

There are several other projects that you might be interested in, and it is worth searching the net for them.  One other PC emulator that springs to mind is called BOCHS (http://bochs.sourceforge.net/).

If you are interested in finding out more about PC emulation you can take a look at this WIKI http://circle.ch/wiki/VirtualComputing it contains some useful links for both BOCHS and QEMU.  There also appears to be a GUI for QEMU (http://www.davereyn.co.uk/qemu.htm) that will make the tool even more useful.

So, go on and see if this little tool is going to be useful to your school.