Policy
Require uppercase letters
Use this policy setting to configure the use of uppercase letters in the PIN. If you enable this policy setting, Windows requires the user to include at least one uppercase letter in their PIN. If you disable this policy setting, Windows does not allow the user to include uppercase letters in their PIN. If you do not configure this policy setting, Windows allows, but does not require, uppercase letters in the PIN.
5c82996960ef MSPassport_UppercaseLetters Registry
Copy registry mappings
HKLM\SOFTWARE\Policies\Microsoft\PassportForWork\PINComplexity\UppercaseLetters (enabled) = 1
HKLM\SOFTWARE\Policies\Microsoft\PassportForWork\PINComplexity\UppercaseLetters (disabled) = 2 Policy notes
Use this policy setting to configure the use of uppercase letters in the PIN. If you enable this policy setting, Windows requires the user to include at least one uppercase letter in their PIN. If you disable this policy setting, Windows does not allow the user to include uppercase letters in their PIN. If you do not configure this policy setting, Windows allows, but does not require, uppercase letters in the PIN.