Do you see your contacts with codes in their name? (like ·$2name)
Do you see the Plus! menu? If you don't, Messenger Plus! Live isn't running.
If it is running and you can see the colour codes in your contacts names, do the following:
You need to uninstall Messenger Plus! Live and Windows Live Messenger from Add/Remove Programs, then delete the folders in Program Files, then download and install them.
Make sure that when you are installing Messenger Plus! Live, Windows Live Messenger is not running.
Screenshots would also help.
Edit:
BLEH, nevermind.