I recently did a MED-V project to help remove technical blockers for a Windows 7 rollout.  MED-V is a useful tool for corporates to make use of a feature of Windows 7 Enterprise called Windows XP Mode.  There's a link to the MED-V product pages below, but the way to think about MED-V is as a creation, delivery and management service for Windows XP Mode images in a corporate environment.  Windows XP Mode is a great solution for resolving application compatibility issues with Windows 7, but try managing the Windows XP Mode images when you have more than a handful of users, it's not easy - that's where MED-V comes in.

Microsoft Windows Enterprise: MED-V

Microsoft Desktop Optimization Pack (MDOP) Technologies TechCenter

TechNet: Microsoft Enterprise Desktop Virtualization

The Official MDOP Blog

While working with MED-V I can across a couple of issues that will probably affect most other users of MED-V.

  1. When a second user logs on the a desktop running the MED-V client there are permissions issues.with the workspace which means it fails to start resulting in the workspace failing to start for any subsequent users.  I worked out that there are file permission issues which I resolved by giving Domain Users Full Control of the folders, but the workspace fail to load - There is a workaround for the multi-user scenario. This is no longer required in MED-V v2 as shared workspaces are supported out-of-the-box.
  2. Some applications fail when the Windows XP Mode image uses NAT (Shared Networking) - Here is an article on the MED-V blog that might be helpful in troubleshooting failure to connect to domain resources using NAT.
  3. The client has multple IE6 based applications, but MED-V isn't granular enough when it comes to chosing which websites must be viewed using Windows XP Mode.  The options MED-V provides are Domain Suffix, IP Suffix, or All Local Addresses.  How can I configure MED-V web rules for specific websites, primarily internal websites but with/without the domain suffix? - MED-V v2.0 will be offering much more granularity for redirection. There is no workaround for 1.0 unless the MED-V administrators also control DNS and can make adjustments there (such as  adding CNAMES).  Here is the v2.0 Beta announcement which talks about where you can register and download the code and also mentions the options for Internet Explorer redirection in v2.0.

I hope you find this information informative.