ASP intranet login Windows auth - User locked but not in AD- Where do i unlock?

I've come acress a problem on a intranet-web page where some users can't login because the accounts are locked. Probably because of invalid password but the users account in AD is not locked. I dont know anything about how these things are connected. They use internal windows authentication. IIS on a windows 2003 server.

This is probably not enough information for someone to help me but what steps are necessary to proceed and what do you need to know to help? link to image of web folder