Windows XP Inside Windows 7: The “XP Mode”

I’ll dare saying that you’ve probably already heard of the “XP Mode” lurking within the Windows 7 RC.  Don’t get it wrong – it doesn’t mean that the Windows 7 OS can run in Windows XP mode (although there are compatibility shims for applications that can emulate whatever version of Windows that you want).  It means that the new Virtual PC Beta, installed on top of Windows 7, can provide a seamless experience for installing and executing applications on a Windows XP virtual machine.  The seamless experience is achieved by showing the application window “outside” the virtual machine – similar to the UI that Parallels and VMWare Fusion (Unity) provide for the Mac.

I wouldn’t be telling you this rehashed piece of news if I had nothing to add.  My significant other’s PC, running the Windows 7 RC as of a few days, has a (fairly) expensive scanner attached to it – an HP Scanjet 5590.

Unfortunately, our attempts to install the custom scanner software on Windows 7 were doomed to failure.  I tried the Vista compatibility mode, the XP compatibility mode – nothing seemed to help.  The funny thing is that the drivers automatically found by Windows Update were perfectly good – but the custom scanner software has the ultimate “Scan to PDF” option, which streamlines the process of scanning several double-sided pages to a single PDF without having to combine individual image files by hand.

So what I did was install the Virtual PC Beta on this machine and launch the preinstalled Windows XP virtual machine.  It booted up, configured with 256MB of RAM and a network connection, and then all I had to do is attach the scanner (connected to the physical host via USB):

… and install the custom HP scanner software.  Subsequently, I shut down the virtual machine and voila – the Start Menu of the Windows 7 host shows the custom scanner application installed within the virtual machine:

Next, I launched it, and after waiting for a few seconds we have the XP application showing a window on the Windows 7 desktop, and working perfectly, scanning pages and pages of text as if it were running natively on the physical host.

The meaning of this for application compatibility is probably best described as a silver bullet.  While I find it hard to imagine that home PC users will find it convenient to install a custom virtualization solution, install Windows XP within that solution and then install applications on that copy of Windows XP – I find it perfectly easy to believe that home PC users will be able to install applications in the preinstalled virtual Windows XP environment and use them directly from the Windows 7 Start Menu.  Wow.