Fixing ASP.NET MVC 3 Install Error Code 0x80070643

While preparing to record a video walkthrough of the action filters tutorial I recently published, I noticed that I was having some issues with syntax coloring and Intellisense in my Razor views. Now, given the number of CTP, beta, and RC releases of ASP.NET Web Pages, MVC, etc. I either have, or have had, on this machine, that didn’t come as a great surprise. So after trying a couple reboots to see if it’d clear up, I went ahead and uninstalled ASP.NET MVC 3 and ASP.NET Web Pages, on the off chance that some component was still using an older version.

So far, so good. The tricky part came when I attempted to reinstall ASP.NET MVC 3. As is my habit these days, I went to do the install via the Web Platform Installer, since it provides a quick and easy way to install various features along with any dependencies they may require. But while WebPI reported the install as having been successful, MVC 3 wasn’t showing up in the list of installed programs in Control Panel, and I wasn’t able to open MVC 3 projects in Visual Studio. Hmmm…

Obviously, I couldn’t give up there, so I trundled on over to to grab the downloadable installer, and give that a try. Alas, this failed as well, but at least I was able to get a link to the log file, which reported the error code 0x80070643.

That led me to the blog post here, which had a suggested workaround for the same error code in the installer for the MVC 3 release candidate. A commenter managed to suss out that it was a patch installer that seemed to be at the root of the problem, so armed with that knowledge, I unpacked the ASP.NET MVC 3 installer (using 7-Zip), located the patch installer and ran it separately, and then provided a path to vs_setup.msi when prompted (ended up downloading the ISO from MSDN, since IIRC I used the web installer to install VS 2010 in the first place). Once the patch was installed, I re-ran the ASP.NET MVC 3 installer (bypassing the workaround suggestion of running all the individual MSIs, since that seemed to have more potential for issues), and the install worked fine.

Best of all, syntax coloring and IntelliSense are working again. Huzzah!