Virtual Device Driver Error Message in 16-Bit MS-DOS Subsystem
View products that this article applies to.
This article was previously published under Q254914
For a Microsoft Windows XP version of this article, see 314452.

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry

After you install some programs, one of the following error messages may appear when you attempt to run 16-bit programs:

16 bit MS-DOS Subsystem
drive:program path
XXXX. An installable Virtual Device Driver failed DLL initialization. Choose ‘Close’ to terminate the application.


16 bit MS-DOS Subsystem
drive:program path
SYSTEMCurrentControlSetControlVirtualDeviceDrivers. VDD. Virtual Device Driver format in the registry is invalid. Choose ‘Close’ to terminate the application.
In some cases, clicking Ignore allows the program to run properly, but the error message continues to be displayed when you start 16-bit programs.

This behavior can occur if the following registry value has become corrupted:
This issue may occur after you install a 16-bit program, or a program that uses a 16-bit installation program, that is not Windows 2000 compliant.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

Start Registry Editor (Regedt32.exe).
Locate and click the following value:

On the Edit menu, click Delete.
On the Edit menu, click Add Value.
Type VDD in the Value Name box, click REG_MULTI_SZ for the Data Type, and then click OK.
The Multi-String editor appears. Leave this entry blank and click OK.
Quit Registry Editor.
If the above steps do not work, or if you are unable to create the VDD key, it may be necessary to also delete and recreate the whole VirtualDeviceDrivers registry key.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

These error messages can also occur in Microsoft Windows NT 4.0 if this key is manually deleted for testing purposes.
The information in this article applies to:
Microsoft Windows 2000 Server
Microsoft Windows 2000 Advanced Server
Microsoft Windows 2000 Professional
Microsoft Windows NT Workstation 4.0
Last Reviewed: 12/3/2003 (3.0)