Check http://social.msdn.microsoft.com/Forums/en-US/sqltools/thread/abf50e00-c9b0-4809-9e61-43ed8a53e968

>A client has sent me a database. However, on that one, I cannot restore it. The messages says:
>
>"The media set has 2 media families but only 1 are provided. All members must be provided."
>
>What should be done?