我没有更改密码时，sa登录失败

I've been developing a winforms app tied to sql server. I haven't rebooted in a while. Today i rebooted and now I can't log into sql. I used every account I know and their passwords including one that was working just before i rebooted and i get a 'Login failed' . I did take the database I use offline just before starting and I do have backups before then. I've been developing a winforms app tied to sql