Need clarification on Account lockout policy?

Hi Team,

AD : Windows server 2008 R2

Users Count : 4000+ Users

In my domain, no account lockout policy in place - its set for 0 invalid attempts. For auditing and security reasons, need to apply account lockout policy in my domain.

So, to observer, i have implemented the lockout policy in the domain. But then, there are lot of users started complaining about the account lockout issue and my Help desk is filled with lockout tickets.

I think the majority of the issue is causing due to the saved passwords in the PCs. Then after this incident, i roll backed my changes. 

Please advice, how i can tweak this and apply lockout  policy in my domain.

Regards, Dev