Need HELP on my computer!! What happened to MSN Messenger?

Lost some icons off my task bar. And clicking on Programs, they are dead and do nothing. Help!!
~Cathie

start:programs:msn messenger/windows messenger

Thanx - we obviously fixed it. But right now as I look at my taskbar I see my little green people are'nt there. What's up with that??
~Cathie

If explorer quits and than restarts, all programs will close except Volume control and Task schedual (on my computer). A simple restart of the computer will get everything fine and dandy again:)