You still didn't drill down to the correct key. If you read my post above, i said:
No matter. I can see now your registry doesn't contain the shell extension subkey which explains why your IE won't open in your first (problematic) account. Quite strange... i'm surprised that the same problem doesn't occur in the new account you created... which leads me to believe it's something in your current user key or something in the user account settings that have gotten corrupt somehow. It's probably the latter in my opinion since this the missing subkey is in the classes root key.
Drill down to the following subkey in the same tree that you posted your screenshot. This time, make sure you drill down exactly to the correct subkey.
Highlight the Application subkey and look in the right pane for the default value; There should be a string value that says IExplore. If that is the case, we could try creating the missing subkey.
Since you're using multiple browsers, it may or may not say that. If it doesn't, then make a full backup of your registry just in case we need to revert back to it.
Again, going back to the original subkey I told you to look in, under the htmlfile key, create a subkey called "ShellEx" exactly as is w/out the quotes. Then create another subkey under that called "IconHandler" When you're done, you'll have a subkey exactly as I have typed in my posting above. Click on the subkey IconHandler and highlight it; in the right pane, you'll need to Right-click and create a new String value and give it a name of "(default)" - don't use the quotes. Once that's done, Right click on it, 'Modify' and input the following string data -- just copy and paste:
Make sure you create this subkey EXACTLY as i've instructed.
Exit the registry and reboot your system.
If this method does not work, you may have to just transfer everything to the new user account you created.