I haven't created a keychain login password but I'm being asked to enter it

I'm being asked to enter my keychain login password. What is this? I don't remember ever creating one to be honest. is there a way to reset this?

I'm being asked by Microsoft outlook for this, to use my information stored within keychain, the trouble is I can't get the message box off the screen and can't restart the MacBook (normally, anyway).

I could do a force shut down. but thought id ask for any help first.

cheers Dave