I recently upgraded to Windows 7  from XP, which means a clean install.  I had been using Visual Studio 6 on XP and decided to upgrade.  It *looked* like VS 2005 was more complete so I started there.  But I got the error (shown in VS 2008, but it is the same error)

as soon as I created my first project.  Real helpful, right?  See anything missing?  How about the key they were trying to access.  Dumb.

Anyway, I installed VS 2008 (version 9.0.21022.8 RTM), thinking that this error was corrected.  Many people reported it and Microsoft has simply closed the reports starting it was irreproducable (http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=302366)

There are a variety of solutions out there.  Some of them are very broad brush.  By broad brush, they can run for 2 hours.  There have been many reports of systems being unusable at the end of two hours.  At the end of the discussion, is a fix from "Random Weirdo" that involves registry editing. 

We have had success with this instruction and it looks like there is a single registry key each for Visual Basic or C# that needs to be edited.  On a brand new install, the key has to be created by the Visual Studio installer.  It looks for all the world like Microsoft did not try installing their own Visual Studio on their own Windows 7.

Here are the step-by-step insructions.

1) Exit Visual Studio.  If you do not do that, the registry key will be held open and you cannot edit it.  Exit now.

2) In the Registry Editor, navigate to the key to change.  For Visual Basic, the key is HKEY_CLASSES_ROOT\VisualStudio.vbproj.9.0 and for C# it is HKEY_CLASSES_ROOT\VisualStudio.csproj.9.0

if you left click the key, you will get this error message.  Click OK to dismiss message box.  This is the problem we are about to fix. 

3) Instead, right click and bring up the context menu. 

Click Permissions to continue.

4) Dismiss the pointless warning which comes up. 

5) Click  Add

6) Click Advanced

7) Click Find

8) You can make your own choice whether to allow just yourself. to be done with this annoyance once and for all, I picked Everyone.  Then click OK.

9) The object selected is shown.  Click OK.

10) Click Full Control.  The Read box will also be checked.  Click Advanced.

11) click Owner

12)  Pick an owner.  I picked myself, rather than Admins generally because I felt it was less likely to fail.

13) I then clicked Apply to insure that my name showed up as current owner.  You can see that it has in this screen shot as opposed to "Unable to display" in previous step.  Click OK

14) Click your final OK

15) ... and the registry view has changed.  Now when we left click or select the HKEY_CLASSES_ROOT\VisualStudio.csproj.9.0 key, we see that this is a Visual C# Project file.

16) Go back to Visual Studio and create your Visual C# project (or Visual Basic project if you applied this to the Visual Basic key).  Some say you need to restart Windows but I did not find it necessary.  If you use both Visual C# andVisual Basic, you must go through this process twice. There is surely a similar process for Visual C++