Delete old email account

I am helping a friend with her computer. She changed her ISP and we set up the new email account in Live Mail and got it working. I deleted her discontinued ISP account from Live Mail. Everything was just fine. Unfortunately, she did a restore to earlier date on her system and it brought back the old mail folders but not the account information in properties. Now when she opens Live Mail she gets a sign-in screen for the old ISP account and she has to cancel before she can continue with her mail. I have looked in the Accounts tab in Mail and there is nothing in there about the old account. Does anyone know how I can solve this? I am hoping that I don't have to go into to registry.