More on XP and a corrupted mailto registry key

Was happy to receive a lengthy comment on my post from Charles Gaefke (nice to know one is being read sometimes). Here’s his email, without editing.

Hi, about your blog …

The same thing happened to me, except I don’t use outlook express. I use Mozilla Thunderbird. Things worked fine for a while, then suddenly, yesterday, it started asking me if I wanted to make it default or not. Of course, saying yes, no, or never ask again didn’t do a thing.

Before I go into what I did to fix it, let me explain this happened to me once before. Symptoms were the same: click a mailto: link, get about 30 IE windows with “page can not be displayed” and thunderbird always asking me if I want it to be default. I found the mailto key was unreadable. What I tried doing then was the WRONG THING to do. I tried changing the security permissions on the parent key (which happens to be the hive) hkeyclassesroot and propagating it to all the children. BAD MOVE. From that point forward Windows would hang at the welcome screen and never get to the point of logging in. Reinstalling Windows fixed that one, but that’s never painless. In this case, I keep another bootable partition for just such an emergency. What I didn’t realize was my bootable partition was XP64, which of course won’t run XP32 install. So I had to install from CDROM, then create a third partition, install to that partition (because I don’t like using c:\windows as my windows folder, and you can’t override that from CDROM), delete it from the C:, reinstall, and now all is well.

Needless to say, I wasn’t happy when I just started getting the “would you like to make it default?” message. :)

Your suggestions didn’t work. I wasn’t able to apply the permissions as the user or as another user (in this case Administrator).

What I did, which appeared to work…

I went into Set Program Defaults. For Email client, it was set to none. I changed it to Mozilla Thunderbird, and applied. Windows took a long time, but it didn’t throw an error.

Went back into RegEdit, and the key was still locked. I tried adding some users, no go.

What I did, is try to add the administrators group. I got access denied, but I didn’t quit, so the permissions were still there. I then went to advanced, owner, and try to pick a new owner of “administrators”. It gave an error, but it didn’t stop at that tab and went back to the “add permissions” tab. Then it would let me apply it. Closed RegEdit, reopened, and now I could open the MailTo key, and I saw the subkeys, but they weren’t accessible either. Went through the same gyrations for each of the subkeys until they were all set, then turned on “reset child permissions to inherit” on the MailTo key, and now all in good.

Now for what caused it.

I installed the Office patches a long time ago. So I don’t think it was that.

What I do think it…

My wife uses Hotmail under her account. Thunderbird is the default client, but it isn’t configured. So everytime she would click a mailto, thunderbird would pop up asking for configuration. She’d cancel it. This happened enough that she called me at work to see if could fix it. I think I can talk her into using thunderbird as the client through Hotmail, but if I can’t, I think this error may come back.

Fortunately I think I know how to fix it now.

Charles.

Strange that it didn’t work. I had exactly the same problem on a second machine after I installed the Office patches, and I used the same solution (mine) and rectified it in no time at all. The way I see it, I’ve always had a dual user profile/account on all systems; perhaps that makes a difference.

Incidentally, that’s another lesson I learned the hard (very hard) way a long time ago, when my account profile got corrupted and I had the most hellish time getting back into my system, accessing my files and getting to work — only to find that all my heavy customizations and settings had been torched. Now I just have a second profile and, periodically, I copy registry keys over to that profile. It’s like a mirror account: all settings are identical, just the login is different. Both accounts even access the same data folders! Whether you use either of these solutions, I’d strongly recommend creating a profile account anyway.