How to stop passwords from expiring?

My company had a pasword policy that was set to expires in 90 days. This became too frequent and frustrating for our users. I was asked to remove it and set it to not expire. I did, yet it still doesn’t work. I checked every policy in my AD and did not find any policy that would set password to expire. All the policies currently has it set to not defined. I finally figured out all the local machine policy has passwords expires in 42 days. How is did this happen? Does anyone know how I can reset all the local machine back to not have the password expires? Can anyone advise how to calculate effective password policy or know of any white papers that talks about this.

Thanks