Lost public folders during exchange migration from 2003 to 2010. removed the exchange 2003 administration group using asdiedit tool. It then removed my exchange 2010 public folder database. How do I get it back

That was a huge mistake. In addition to losing the public folder system object, now all of your users whose mailboxes have been moved will find that their free-busy is broken. You should restore the Exchange 2003 administrative group and everything underneath it through an Active Directory authoritative restore. When you have the public folder system object back, you can create a new Folder Hierarchies object in the Exchange 2010 administrative group, and then move the Public Folders object to it via drag and drop. Do NOT remove the Exchange 2003 administrative group. You can remove everything under it, however (except the Public Folders, which which you will have moved). Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."