Normally you will see your online and offline contacts on Windows Live Messenger. Your offline contacts cloud your overall view on who is online and offline. But you can see your online contacts seperately with changing a setting on WLM options :
1. Click on your name/title > Options
2. Go to Layout
3. To see your offline contacts in a separate category, check "Show offline contacts in a separate catagory" box at the bottom, click Apply and OK.
4. To hide your offline contacts completely, uncheck "Show Offline Contact" box, click Apply and OK.
5. You're DONE.
via The Productive Organizer