Windows XP Mode Internals – Part 1 (Overview)

Yesterday, Paul Thurrott and I revealed some pretty exciting news surrounding a new feature in Windows 7 called Windows XP Mode (formally Virtual XP). While Paul is working on the high level stuff – screenshots, features, etc. – I’m going to start with the more nitty gritty things the tinker tot inside us is burning to know (and play with).

But first, an overview.

To start, Windows XP Mode (XPM) is a new tight-knit solution of several already-available-today technologies. At the core of XPM are Virtual PC 7 (VPC) and the Remote Desktop Protocol (RDP) protocol. While VPC’s purpose is pretty clear, RDP’s may not. XPM makes heavy use of RDP features such as Remote Applications Integrated Locally (RAIL), compositing, and multi-monitor support.

Windows XP Mode will be installable on three Windows 7 SKUs: Professional, Enterprise, and Ultimate. More specifically, the license policy VirtualXP-licensing-Enabled is only installed and present in these SKUs, of which XPM checks upon use. The timeline for XPM release is still under wraps, but we’ve been told to expect a beta version next week and a final release roughly around the Windows 7 RTM timeframe.

Now, what are you going to see in terms of installable components? XPM comes in two parts – The VHD package – containing a preinstalled, shrink-wrapped copy of Windows XP with SP3 — and an optional Windows update (KB958559) that deploys a variant of the upcoming Virtual PC 7 (VPC) product. After installation, your XPM installation folder will contain an expanded VHD, a text file containing the product key, and some random words in license agreement form.

In the Start Menu, you’ll see three items: A special folder containing pointers to installed virtual machines, a folder of auto-published shortcuts (more on this later) to installed applications within the virtual environment, and finally a shortcut that fires up the VPC instance of Windows XP.

As I’m currently using older bits, you’ll still see reference to Virtual Windows XP in these shots. This may change when the public beta becomes available.

After a fresh install, and first invocation of XPM by clicking the Virtual Windows XP shortcut in the Start Menu, VPC will configure the virtual machine for use. This process isn’t exactly speedy but Virtual PC provides a real time status as to what’s going on.

VPC first boots Windows XP. XPM then communicates with Windows XP and automatically (and silently) walks through the painful OOBE process, individualizing the virtual machine with details providing during install (e.g. username, computer name). Finally, XPM bootstraps the Windows XP install with various drivers and components necessary for XPM to work smoothly. For those familiar with VPC or VMware, this step is similar to installing the “integration components” or “tools” package included with the virtualization suite.

After all is said and done, you’ll be presented with a rather boring virtual machine view. It is here you’ll install your applications. Applications that install a shortcut to the All Users Start Menu will have their shortcut automatically published to the host machine within the Virtual Windows XP Applications folder (see above figure). For less well-behaved applications (or inbox applications like Internet Explorer 6), you can simply create a shortcut manually and it will (eventually) appear in the host Windows 7 environment.

Over the next few posts, I’ll be focusing on specific areas of Windows XP mode.