http://windows.microsoft.com/en-us/windows7/install-and-use-windows-xp-mode-in-windows-7

XP Virtual Machine

http://www.microsoft.com/en-us/download/details.aspx?id=8002

This patch may not be necessary on all systems.

http://www.microsoft.com/en-us/download/details.aspx?id=3702

• Make sure you're running Windows 7 Professional, Enterprise, or Ultimate. To find out which edition of Windows 7 you're running, click the Start button Picture of the Start button, right-click Computer, and then click Properties.

• Find out whether your computer's CPU is capable of hardware-assisted virtualization. To check, download and run the Hardware-Assisted Virtualization Detection Tool.

http://www.microsoft.com/en-us/download/details.aspx?id=592

• If you receive the message “This computer is configured with hardware-assisted virtualization,” you can run Windows Virtual PC and Windows XP Mode. See the instructions below.

• If you receive the error message “There is no hardware-assisted virtualization support in the system,” your computer's CPU doesn't support hardware-assisted virtualization. You can still use Windows XP Mode by installing an update to Windows 7. See Why am I receiving errors about hardware-assisted virtualization (HAV) when I try to use Windows XP Mode and Windows Virtual PC?. Be aware that XP Mode will run much better if hardware-assisted virtualization can be enabled.

http://windows.microsoft.com/en-us/windows7/why-am-i-receiving-errors-about-hav

• If you receive an error message saying “Hardware-assisted virtualization is disabled,” this means your computer supports hardware-assisted virtualization, but you need to change settings in your computer's basic input/output system (BIOS) to turn on hardware-assisted virtualization. Procedures to turn on virtualization settings in your computer's BIOS vary depending on the BIOS manufacturer. Check the information that came with your computer or go to the computer manufacturer's website.

• Click Start, All Programs, Windows Virtual PC then click Windows XP Mode

• Shutdown the Virtual Machine
• Click Start, All Programs, Windows Virtual PC then Windows Virtual PC
• Right Click the Virtual Machine you want to configure then select edit.