I had the same problem. Microsoft TechNet addresses how to fix this exact error message. Go to:
http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q254914
If the link doesn't take you there, then go to their Home Page at: http://www.microsoft.com/technet
In the left pane, click "Troubleshooting and Support"
In the middle pane, under "Resources\Troubleshooting", click "Search the Knowledge Base (KB)"
Under "my search is about:" select "Windows NT Workstation 4.0"
Under "My question is:", type, "virtual device driver format in the registry is invalid"
Leave all other options as they are.
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