If you need Windows XP for backward compatibility in a virtual machine on almost any computer, this is how to get it:

Step 1: go to the MS download page for XP Mode Windows_XP_Mode. 

Step 2: if you have Windows 7, skip to step three. Otherwise, you will need to download and install a Windows 7 virtual machine. This is pretty easy, since MS has a list of these machines also for free on their website: Windows Virtual Machines. These can be run with you virtualization platform of choice. I use VMware, since the integration with your host OS is very advanced.

Step 3: Run Windows 7 installation or VM and install the XP mode executable file. This will produce a VHD with the installation inside it and an activation product key.

Now you have two options, you can either use the provided XP virtual machine VHD, or simply perform an installation with a CD or ISO and use the supplied product key.

The Windows XP ISO is still available at the following website:

www.getintopc.com

This site has a lot of untouched ISO’s and binaries for both current and discontinued OS’s and programs.