Remember - This is a public forum so never post private information such as email or phone numbers!
Ideas:It appears that someone is signing in my "Windows Live" from another computer. How do I stop this?
You are off topic for the forum that you posted to, which is dedicated to Microsoft Security Essentials
Help for Windows Live Messenger (downloaded from http://download.live.com) can be found here: http://help.live.com and it can be discussed here:
http://www.microsoft.com/communities/newsgroups/list/en-us/default.aspx?dg=microsoft.public.windows.live.messenger&cat=en_us_0f43cf19-5af1-4912-9a55-f5ff1f9fd904&lang=en&cr=us
You may also want to review this post:
https://windowslivehelp.com/solutions/accounts/archive/2008/10/25/what-to-do-if-you-think-your-accounts-been-stolen.aspx-steve