You can remove it, but I don't recommend.
Visit http://www.tweakxp.com/
and search yourself for the answers. The tweak is in there. Bear in
mind that once this change is applied, it is irreversible.
To stop these 2 from signing in and out all the time, change the
options.
Open MSN Messenger. Click Tools, Options
Under the General tab, uncheck the box which says "Automatic
sign-in when connected to the Internet.