Managing passwords for dependent windows services in TPAM
Insufficient permission on Windows system could cause password change failures
If you have set up Windows Service accounts to be managed by PPM / PAR and the passwords are not changing properly, it could be a permission issue on the local Windows system.
The user that you have set up to manage the services should be a member of the Local Administrators group on the system. That will ensure it has the appropriate permission to update the services.
This Microsoft article has more detail about managing Windows Services