Is the problem in Firefox, before you get to Thunderbird? In that case:

Could you check the following setting to see whether Firefox has gotten confused about the account you want to use for mailto: links and the "Email Link" feature: Change the program used to open email links.

If the problem occurs once Thunderbird receives the hand-off from Firefox, hmm, a moderator can move your question to the Thunderbird forum.

Thanks for your prompt reply. Yes, the problem is in Firefox, before I get to Thunderbird. Instead of sending me directly to Thunderbird (I checked, and yes, Thunderbird is still my default email program) it sends me to the "Account Wizard" pane, first screengrab below. This (alleged) wizard asks me for my name & email, and finally, for my NNTP news server, which is something I don't have or want. There's also a (very) blank Thunderbird "Write" page in the background - second screengrab below.

It looks like Firefox is sending the request to Thunderbird, but for some reason, Thunderbird does not think you have an account configured. However, if you're not sure, try the steps in the article I mentioned.

I tried all the steps in the article you mentioned, but got the same outcome. My Thunderbird account configuration has not been changed, and I've never had anything to do with any newsgroup. Any other idea of what else I can do?

Hmm, I think a Thunderbird expert needs to look at this. I've flagged this thread to move over to the Thunderbird forum.

Thank you. Will I get an email from them if someone comes up with a solution?

what happen if you just open Thunderbird and click write? I am guessing you don't use it much and the problem is far more widespread than your initial post indicates, like it has lost all of your existing accounts.

I open Thunderbird and click "Write" many times every day, from all three of my email accounts, and nothing like this ever happens. I can (and sometimes do) cut and paste a URL into the body of what I'm writing, but the email-a-link in Firefox button faster, especially when a link is all I need to send someone.

Hi calanger, does Thunderbird start normally if you use this path in the Windows "Run" dialog (hold down the Windows key and tap R), or does this do something different than the shortcut you normally use to start Thunderbird:

"C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe"

Hi Matt, do you think the problem could be that mailto: is starting Thunderbird in a different or new profile (discrepancy between the user's preferred profile and the default profile in profiles.ini/installs.ini)?

When I open Thunderbird using Run, I get the screen in the attached screengrab, because it's opening the program using the (unused) copy of the .exe on my C drive. The shortcut I use (and have for many years, no recent changes) opens Thunderbird on my D drive, where the program and all its files reside. FYI, for a variety of tried-and-true reasons, I keep most of my program files and data on partitions other than C that I've set up.

Hi calanger, it's possible the Windows Registry has mailto wired to the Thunderbird installation on C. (Why is that install still there??) If you are familiar with RegEdit.exe, you could look at this key to check:

HKEY_CLASSES_ROOT\Thunderbird.Url.mailto\shell\open\command

Can you trigger your regular Firefox to update the default mail client settings and see whether it takes care of this problem: Make Thunderbird the Default Mail Client.

o Options shows Thunderbird as my default mailto application (first attached screengrab)

o Regedit shows the wiring to the C drive copy whose existence (till now) I never thought about. (second screengrab)

Sorry, I meant in Thunderbird, not Firefox: Make Thunderbird the Default Mail Client

The purpose of that is to see whether the Thunderbird on D drive will update the Registry to point to itself.

Just did that, registry still points to the C drive .exe

Where is your copy of Thunderbird and why is it not on your C: drive? I am starting to think this is the portable apps version and their wrapper is not working for you.

My copy of Thunderbird is on my D drive, where it's been since Thunderbird was Netscape Mail. Until about a week ago, the "Email a link to this page" button has worked flawlessly since it was part of the toolbar, .

I've used a multi-partioned disk setup for decades, with the OS on my C drive, and separate partitions for my business, non-business, pagefile, and virtual machines. This goes back to when I had, for speed reasons, separate physical drives for each partition, but still helps with organizing things, controlling fragmentation, and ease of recovery of corrupt files,etc. If this is what's causing (after all this time) this one problem with Thunderbird, it will be a first.