Windows Live Messenger will not appear in the taskbar, although in the computer has Windows Live Messenger installed.
Here is how to solve it. Go to Start Menu, then go to 'All Programs', hover to 'Windows Live' and click application named 'Windows Live Messenger'. Once it is running, go to 'Tools', then 'Options' and 'Sign In' tab. Mark 'Automatic Run'.
If 'Tools' menu is unable to choose, one of the drop down boxes to the far right called "Show Menu" needs to have "Show menu bar" marked.