Try entering Admin as the account name while leaving the password field blank.
If that opens your files, check the settings in File Options. The default setting for non-password protected files is for Admin to be entered in the account name field with the password field left blank. Unless someone has used security settings to define a new full access account or to change/remove the name of the admin account, this should be enabled for each of these files.
That worked! Thanks soooo much.