Here are your Windows 7 XP Mode + Shoretel PCM instructions:

Step 1) Have a PC with Windows 7 installed.

Step 2) Download the XP Mode setup packages from Microsoft:
Follow the instructions on the Microsoft page. You basically download Virtual PC first and install it, and then download the XP Mode virtual machine second.

Step 3) Run the Virtual XP Mode VM by going to Virtual PC in the Start Menu.

Step 4) Now you’re looking at a virtual machine of the XP VM. It looks (and is) just like XP. Go ahead and install the Shoretel client onto this PC, via your Shoretel installer page: http://YOURSHORETELSERVERNAME/ShorewareDirector/ClientInstall

Step 5) Configure the Shoretel client with your server name, user name, password, etc.

Step 6) Shut down the XP Mode VM (via Shutdown or the menu at the top of the window).

Step 7) Launch the Call Manager from your Windows 7 start menu (Virtual PC, Virtual Applications, Shoretel Call Manager).

That’s the procedure. Note that the call manager will take a few minutes to start up when you initially launch it, as it takes a couple minutes for it to load up the virtual machine in the background. Let me know if you have any specific questions about any of the steps.