If you try to install the ASP.NET MVC 3 Tools Update announced at MIX11, and you had previously installed (and then uninstalled) the Visual Studio Async CTP or the Visual Studio Async CTP (SP1 Refresh) installed, you might still get this error message:
This product is incompatible with the Microsoft Visual Studio Async CTP. Please uninstall the component, then try to install this product again.
If you do, I have a solution for you!
Simply uninstalling the Async CTP isn’t enough to get past the checks that the MVC 3 Tools Update is looking for. To get past this issue, you’ll have to go Registry diving and perform some minor surgery.
DISCLAIMER: I am suggesting to you a solution that worked FOR ME, but might not work for you. I am NOT with Microsoft support, and will NOT warranty your system if you do this, or some other crazy thing and brick your computer. This is definitely an instance of “it works on my machine” and your mileage may vary. Use at your own risk. Void where prohibited. Please drink responsibly.
With that out of the way – the operation is actually pretty simple: start Regedit, navigate to the following registry key and delete it:
Make sure you’re deleting the entire key from the tree view, and not just the parts from the details view. If you’re nervous about doing this, you can always right-click on the key and export it to your computer before you delete it.
And that’s it! After the key is gone, re-run the installer and you should be good to go.
Many thanks to Kevin H for using the force to track down this orphaned key for me and helping me get past this annoying blocking issue.