If you received this error after uninstalling any application that takes over the HTML open command 
(including, but not limited to, Chrome & Firefox browsers) you may also need to change the HTM/HTML association in the registry.

Start, click Run, type Regedit in the Open box, and then click OK.

Browse to HKEY_CURRENT_USER\Software\Classes\.html

Right click the value for the .html key and select Modify...

Change the value from "ChromeHTML" to "htmlfile" (or from FireFoxHTML to htmlfile)

Repeat for .htm, shtml, .xht, .xhtml, .xhtm keys

Repeat these steps for htm and .shtml keys if they exist.

 You may also want to check the xhtml and xhtm keys.