User accounts

SUGGESTED

I've been working for months setting up a new system for a Convenience Store operation. I hadn't even looked at User Accounts and was operating as "SysAdmin", I'm pretty sure WITHOUT a password. Today I got to the finish up stage, printing Year End Reports, closing the year etc. and I decided to set up User accounts for the people that would be accessing the system. I set up 3 new users, with passwords and set their access options. Now, when I open the system it asks for a user account (which it never did before). I can sign in as any of the 3 new users I set up, but I can't sign in as "sysadmin" - it wants a password and I'm pretty sure I never did set one. And for the new users I set up, "Users" doesn't even show up in Settings. Any suggestions what I can do to get myself back in as administrator?