I've used Windows Live Mail (Version 2011 Build 15.4.3555.0308) successfully for several years, but yesterday I started getting a pop-up box "Sign In To Windows Live Mail" every time I open the WLM program.  If I click "cancel" in the pop-up, everything seems fine--I am signed in to Windows Live and receive and send emails and so does my wife in her subaccount.  I've had automatic login enabled from the beginning and it seems to still be working.  But if I enter my password in the pop-up, the password is rejected with this message: "The email address or password is incorrect.  Please try again"--maybe because I'm already logged in?  I've reset the password several times, no improvement.  How can I stop this redundant pop-up from popping up?
How do you do mass Deleting of items in the sent file / folder in Live Mail
I updated from Windows Live Mail 2011 to 2012.  Each category shows the number of names next to the category, but the category will not work for sending messages. The category shows as empty when used for emailing or when right-clicked to try Edit Category.  I created new categories, but they work only until the software is closed.  Then they are empty (except that they still show a number next to them).

Since unsuccessfully sending pictures to myself, from one PC to another, Live Mail apprears to be 'blocked' and will now not receive emails. The  error message is 'Unable to send or receive messages for the Btinternet (paulstephen2) account. Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity'.

The emails with attachments earlier sent to myself have not been recieved and seem to be clogging up the email system. Can anyone help please?

I had no bother changing my laptop or Tower PC to get updated Outlook but just do not seem to change it on my Netbook
I go straight to Windows Live mail which I have an Account too. My mail on my other computers does not show up on this one.
When I try to send an e-mail with or without pictures, it goes to the outbox and stays there. It won't go.
I have to look in the email list to ascertain if a new email has arrived.
I can't send mail, error 550 must authenticate. How do I authenticate?
cannot find sent messages once sent out, and when ready to close session, get a command memo if I want to send messages currently in outbox- how do I correct? 
my Windows Live Mail acct has stopped filtering junk/spam.  Everything goes to my inbox.  Can you please help?