The other day, I noticed that the Maya Help was using Chrome instead of my default browser (currently IE). I didn’t see anything in the docs about specifying a specific browser, so I figured it must be something about my system.

So, like I often do, I fired up Process Monitor to see if I could figure out why. And it was pretty simple.

I found that

HKEY_CURRENT_USER\Software\Classes\.htm

was set to

ChromeHTML

even though my default browser was IE.

So I changed it back to htmlfile, and voila, Maya 2012 opened the online help in IE again. There are other, similar keys, but I didn’t touch them:

HKEY_CURRENT_USER\Software\Classes\.html
HKEY_CURRENT_USER\Software\Classes\.html
HKEY_CURRENT_USER\Software\Classes\.shtml
HKEY_CURRENT_USER\Software\Classes\.xht
HKEY_CURRENT_USER\Software\Classes\.xhtml
HKEY_CLASSES_ROOT\.html

Here’s a video walk through that shows how Process Monitor can be used to diagnose and troubleshoot this kind of problem.