Troubleshooting ASP.NET MVC upgrade 1.1 to 2.0

I couldn’t resist the temptation and decided to upgrade my apps to ASP.NET MVC 2… unfortunately I had ASP.NET MVC 1.1 already installed and they didn’t get along well together. While installing Visual Studio 2010 Beta 2, the MVC 2 part would fail to install.

Having decided that I want to uninstall the older version, I tried to do it. Unfortunately the error message was not very comforting:

Please uninstall the Microsoft Visual Studio Tools component for MVC before uninstalling Microsoft ASP.NET MVC 1.1.

Even though I uninstalled all Visual Studio components, the message would not go away, and I was not able to uninstall ASP.NET MVC 1.1 and thus, I couldn’t install ASP.NET MVC 2.0.

Googling and Binging gave me the idea that on Windows 7 x64, the uninstaller does not delete a specific registry key, which is being checked by the other uninstaller. The key is:

HKLM\SOFTWARE\Microsoft\ASP.NET\MVCTools 1.1

After manually running regedit and deleting the specified key, the ASP. NET MVC 1.1 uninstalls without any problems. Success!