The valid range of values for PasswordMinChar is between 1 and PasswordMaxChar.
The value cannot be less than the minimum number of characters implied by other rules. For instance, if at least 1 digit, 1 special character, and a mixture of upper and lower case letters is required by other option settings, then the PasswordMinChar setting must be at least 4.
If you enter a zero or a negative value, the system replaces the value with the system default value and writes an error message to the event log at the next restart.