Break the Hardware Upgrade Cycle with Win4Lin Windows Virtual Desktop Server

Smooth Migration to Linux by delivering Windows to Linux clients via Win4Lin VDS.
Delivering Single Applications to the Linux Desktop

So far, all we've covered is how to get a full Windows XP desktop delivered to a Linux desktop. Although that might be suitable for many situations, there are others when users may require only a single Windows application. How can VDS be rigged to open up an application instead of a full desktop? By tweaking the Windows registry, of course. The Win4Lin VDS manual is the best place to look for current instructions on how to achieve this, but in the interests of sitting down and getting it done with just this copy of Linux Journal, now we provide steps required to deliver a single application.

Ensure Correct Win4Lin Registry Key Value (All Versions of Windows)

Regardless of the application or the version of Windows being used, a Win4Lin registry key must be set or verified first:

  1. Open the regedit application.

  2. Navigate to the HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon.

  3. Ensure the Userinit variable reads exactly B:\mrgpro32.exe. If the value isn't exact, change it.

It doesn't make a whole lot of sense to have users log in to Windows just to run a single application. Therefore, step one—although optional—is to set the master Windows profile to log in a user automatically. Different flavours of Windows have different provisions for allowing automatic log in.

Set Autologin (Windows 2000)
  1. Launch the Control Panel.

  2. Launch the Users and Passwords applet.

  3. Uncheck the box that reads Users must enter a user name and password to use this computer, and click OK.

  4. When prompted, enter the user name and password of the account under which you would like Windows to launch.

Set Autologin (Windows XP)
  1. Launch the Control Panel.

  2. Launch the User Accounts category.

  3. Click Change the way users log on/off.

  4. Uncheck the Use the Welcome screen check box.

  5. Click Apply Options.

  6. Launch the alternate user account editor by clicking Start→Run and entering control userpasswords2. Click OK.

  7. Uncheck the box that reads Users must enter a user name and password to use this computer. Click OK.

  8. When prompted, enter the user name and password of the account under which you would like Windows to launch.

Designate the Single Application to Deliver (All Versions of Windows)
  1. Launch the registry editor by clicking Start→Run. Type in regedit and click OK.

  2. Navigate to HKLM\Software\Win4Lin.

  3. Right-click in the empty right-hand pane to create a new variable.

  4. Select String Value.

  5. Type SingleAppStart (case-sensitive).

  6. Double-click on the newly created SingleAppStart variable.

  7. In the Value data: field, enter the full path to the executable to be launched. For example, to run Microsoft Word, WORD.EXE is not sufficient. The full path of C:\Program Files\Microsoft Office\word.exe (or wherever your Word executable is located and named) is required.

  8. Exit the registry editor, and you're done!

Now when users launch their clients and log in, Microsoft Word will launch onto their desktop right beside their Linux applications. This may not seem like a big deal, because the Microsoft Office suite is nicely supported by Wine and CrossOver Office, but swap out Word for absolutely any other application on your Windows desktop, and the power becomes obvious. Because a full copy of Windows is being brought to bear to deliver the application, there is an almost unlimited number of Windows applications that can be delivered in this manner with zero modification.

Parting Thoughts

Virtualization technology isn't new. IBM has been playing with it since the 1960s. What's making virtualization exciting again is the widespread availability to fast networks and powerful servers. Using Linux to deliver Windows is cost effective in terms of hardware, management and training, and products such as Win4Lin Virtual Desktop Server make the technology easy to install and use. In fact, virtualization technology has come so far that the tricky points are no longer technical in nature; they are logistical. It's more difficult to plan a virtualization strategy than it is to implement one.

Jon Watson ( is a Canadian GNU/Linux enthusiast who regularly contributes articles to the Linux community. When not writing, blogging and podcasting about free and open-source software, Jon frequently can be found in his office polishing his Linux+ certification, which impresses no one but himself.