I have a backup file taken from a SQL Server 2000 database and I'm trying to restore it to a 2008 database. However, I'm getting this error:

An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo) The media family on device 'C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\Backup\customers.bak' is incorrectly formed. SQL Server cannot process this media family. RESTORE HEADERONLY is terminating abnormally. (Microsoft SQL Server, Error: 3241)

I am the one who originally took the backup (years ago). It was a hosted SQL Server. If I remember correctly, I got the backup using some sort of online "control panel"