nearly perfect Rated 5 out of 5 stars

nearly perfect... and a perfect collaboration with add-on "QuickPasswords"
- SPE establishes trouble-free logins with the one exception of the most querulent site in this universe: "https://login.live.com".
It's not possible to login in this misfit with 'Saved Password Editor' nor with the Firefox's built-in passwordmanager.
Admittedly I'm longtime used to get troubles with some software-companies' site-impertinences.
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Thank You for your answer. iMacros for Firefox works perfect. And imho it's not too powerful. Very easy to install, to adjust and then a very simple use. I made a link in the firefox-bookmarks (with a corresponding keyword) to each macro - I do nearly same comfortable and fast logins now to those "SPE"-inkompatible sites as with "Saved Password Editor".

This review is for a previous version of the add-on (2.6). 

You might try iMacros for Firefox. It's quite powerful, in fact a lot more powerful than is needed in a case like this, but it's the only thing I know of right now that is likely to work. I haven't actually tested it with live.com since I don't have an account, but I see no reason it wouldn't.

I recommend using iMacros' master password feature, or the password will be stored unencrypted in the script you create.