Actually, the Troubleshooting add-on is suggested during the process of posting a question; it's an add-on (extension), so you need to give permission for it to install. Of course, when you post using IE that doesn't even come up as an option...

Are you able to access it in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Use Troubleshoot Mode in Firefox.

You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

Thanks for the suggestion. Started in safe mode per your instructions: same behavior -- Help > Troubleshooting Information leads to a hang.

I have re-installed / upgraded Firefox (Mozilla's free download) and yet the problem persists. Help > Troubleshooting Information leads to a hang. Also typing in about:support in the address pane does the same.

Sorry for the delayed response, I was traveling.

To distinguish between Firefox hanging up trying to access settings its own settings information, and having a problem accessing system information, you could try this test.

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run):

firefox.exe -P

Don't delete anything here.

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like TEST or 2-25, and skip over the option to change the profile folder location. Then highlight your new profile in the list and Start Firefox.

Can you access Troubleshooting Information in the new profile? If so, there might be some obscure corruption in your regular profile. If you have the same issue, there could be a problem accessing something from Windows, maybe a permissions problem??

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.