XP mode is not installable on any Home version of Windows 7 (Requires Pro or better). You can however install another VM (Virtualbox, VMWare, etc.) and install a copy of XP in that environment. You will however be required to have installation media and a valid license key for XP.
September 19, 2012 10:15:50 PM
VMware Player in Unity mode does pretty much the same thing and probably better. Player is free but you need to create a VMware account to download it.