First, it sounds like you're talking about MSN's "Instant Messenger" and not "Windows Messenger", but I'll give you a little info on both:
Follow the instructions in the link below to stop Windows Messenger from loading.
How To Disable Windows Messenger
Now to stop the Automatic sign in with MSN Instant Messenger:
Have you tried???
1. Open msn messenger
2. Go to Tools --> Options --> General.... and disable "Automatic sign in when connected to internet"
And if you're using WinXP...
To prevent MSN Messenger from automatically signing in using a registered Microsoft Passport account: click the Start button -> click Run... -> type: control userpasswords2 -> hit Enter or click OK -> click Advanced tab -> select Manage Passwords -> delete all Passport entries -> click OK/Apply.
Then run MSN Messenger -> sign in -> type your passport, e-mail address and password -> uncheck the "Sign me in automatically" box -> save your settings and close MSN Messenger.
Have you tried opening Internet Explorer, Tools, Internet Options, Content tab, "Autocomplete" button, UNCHECK "User Names and Passwords"?
Maybe the answer is at this link will assist:
And if you have Norton antivirus installed, read the info at THIS LINK .
Hope this helps and let us know how it goes.
is there any way to completely remove the windows messenger? and/or how can erase previous accounts from appearing?