In our company, we have some huge very valuable database. Some hours ago, we've started to transfer it from one machine to another. Now we've almost done. But one of the databases on new machine has started to show up a message The header for the file WorkingD.mdf' is not a valid database file header. It has happened at opening. What it might be? How to solve it in couple of days? We are on SQL Server 2008 under Win 7 x32.