Hello David Rañal,
Thank you for posting in Q&A forum.
Q: I have created a GPO to perform this function. But in the setting box, Password box and rewrite Password is not enabled.
A: Yes, it is by design. Because some Group Policy preferences can store passwords. This feature is being removed because password storage is not secure.
The following Group Policy preferences will no longer allow user names and passwords to be saved:
Drive Maps
Local Users and Groups
Scheduled Tasks
Services
Data Sources
The Group Policy Preferences method above is now unavailable.
You can consider the method of LAPS. To learn more about LAPS, please refer to the links below.
https://www.microsoft.com/en-us/download/details.aspx?id=46899
Q: Could you tell me why these sections are disabled or because the GPO that I need to do cannot be done.
A: See answer above.
Hope the information above is helpful.
If you have any question or concern, please feel free to let us know.
Best Regards,
Daisy Zhou
============================================
If the Answer is helpful, please click "Accept Answer" and upvote it.