To reiterate my last reply.
Apparently, you only have one user account ..... "me" which is an admin acct.
Perhaps, someone has disabled the Administrator account which, by the way, is the "built-in administrator account ". It can be enabled or disabled.
I will not recommend using the Guest account at all. Create a standard user account for your guest.
One more thing to confirm how many user accounts do you have in the system......
Start button > click the pointer next to Shut Down > select Switch Users.
Do you see other user accounts listed ?