windows firewall wont start

I have been trying to get into my windows firewall but i cannot get into it. It says that the associated services are not running. But when i go into the services and try to start it, it wont let me start it. Also i noticed that the remote procedure call is dependent on windows firewall. So when i go there, i see that the log on has a password. Is this normal? And how can i get my windows firewall started? Someone please help.
Thankx