Unusual activity dedected on your Microsoft account

I'm wondering if anyone can shed some light on an issue I'm having logging into my live.co.uk email account.

I'm on Windows 7 and using the latest Firefox, and yes, I'm fully aware I shouldn't still be using W7.

I'm getting a message which prevent me logging into my live.co.uk email account. But unlike the usual scam this is not an email within the account, with a link for resetting, it's actually stopping me from logging in until I verify.

But here's where things get confusing. On the little pop-up window it states my correct email at the top, then goes on to explain I have to 'fill in the blanks' to verify. The problem here, however, is that the first two characters of the already completed part of my email are wrong.

For example. Let's say my email was 'example@live.co.uk' it would say I have to fill in the blanks and shows 'ea*****@live.co.uk'

I do have another outlook email, but when I click the option to log in to this, the process is repeated, but for the other email.

Any ideas what's going on or how I get back in to my live.co.uk email account? I've done a virus scan but nothing was found.

PS. I tried to remove the email tags from the above dummy email address above, but it puts them back in when I click save.

This is the pop-up I get when I try to log in at live.co.uk:



And this is what I get after I click the 'verify' link:



The first email (underneath the Microsoft logo) is correct, but the second character in the partly completed email underneath 'Verify your account' is incorrect. And therein lies the problem. I cannot verify the email because the one it gives me the option to select for verification is incorrect.

I have no idea if this is a phising scam, malware or what, but I get this verification issue when I go directly to live.co.uk.

I have tried restarting three times following different scans, and I have tried it on the Explorer browser, all to no avail.

I've tried to download Malwarebytes three times but get a failed installation message each time, and scanned with other virus/malware scanners which all found nothing malicious.