hi i need help with msn messenger

i want to reinstall but i can't....the download bar goes all the way then i get a red cross in it....i have tried to uninstall but i haven't got uninstall msnmsgr on my pc anywhere

i have been to add/remove programmes and msn isn't even in there

i can get on to msn messengar although i am not sure how i am doing it...must be through passport network or something....i run windows 2000 and had messenger 7.0....i am at my wits end

please help!!!
