Visual Studio 2010 Professional error: Designer view not showing

This week, I started the journey of learning ASP.NET 4 with C#.  Unfortunately when I opened Visual Studio 2010 Professional (VS 2010), the designer button was not showing, and the option on the View menu produced the following error:

There is no editor available for ‘c:\user\teadrinkinggeek\documents\visual studio 2010\websites\website2\About.aspx’.

Make sure the application for the file type (.aspx) is installed.

I decided to perform a repair, thinking it would solve the problem.  Instead, the above error was replaced with another error:

The Visual Studio HTM Editor Package did not load correctly.

the problem may have been caused by a configuration change or by the installation of another extension.
You can get more information by running the application together with the /log parameter on the command line, and then examining
the file c:\users\teadrinkinggeek\appdata\roaming\microsoft\visualstudio\10.0\activitylog.xml

I made a ‘painful’ decision to uninstall all things related to VS 2010, and reinstall from scratch.  After 6 hours of troubleshooting, reinstalling VS 2010 again, it worked.

Note: I initially run Visual Web Developer side-by-side with VS 2010.  I uninstalled that package too.  Maybe the two packages caused the problem?  However I spoke to one developer on Twitter, he said he had no problem with both packages working side-by-side.  Maybe it was the way I initially installed them.

If you have the same problem, please backup your work, projects etc, before you uninstall, otherwise you might run into more problems.