The media family on device  is incorrectly formed. SQL Server cannot process this media family

Today in Microsoft community a user raised a question when he was trying to restore a backup on sql server 2008 R2 SP2. And he gets an error message

“The media family on device  '*.bak' is incorrectly formed. SQL Server cannot process this media family”

 /*****************Quick Answer***************************/

 Error: The media family on device  is incorrectly formed. SQL Server  cannot process this media family
--> "Backup is correct and one is trying to restore on lower version or backup was done using some third party tool like lite speed ,red gate etc."

Error: The file on device is not a valid Microsoft Tape Format backup set.”

      Note: SQL server doesn’t support restore from higher to lower version.
--> "backup is corrupt"  
 /***************************************************/

Frequently Used Queries In SQL Server
Frequently used DMV's in SQL Server

Frequently used DBA-Developer Scripts

                          Even when he tried to use restore verifyonly he got the same error. Some how this user manages to open backup file using a hex editor and said source of backup is SQL 2008 R2 and he was confused if he found correct version or his backup is corrupt.

By the time I have read question almost 4 people have answered and everyone has posted their views but no one tested anything. So I have run a few quick tests

Test1: Try to restore data base on lower version

1. Took a backup on SQL 2012 and try to restore on SQL 2008R2 , SQL 2008 , SQL 2005 and SQL 2000
2. Took a backup on SQL 2008 R2 and try to restore on all available lower versions
3. Took a backup on SQL 2008 and try to restore on all available lower versions
4. Took a backup on SQL 2005 and try to restore on SQL 2000

To my Surprise every time I tried to restore with lower version

I got an error: “The media family on device 'C: \dbcheck.bak' is incorrectly formed. SQL Server cannot process this media family”

Test2: Execute all restore options on lower version

1. Restore headeronly from disk =  'C:\dbcheck.bak'
2. Restore filelistonly from disk =  'C:\dbcheck.bak'
3. Restore verifyonly from disk =  'C:\dbcheck.bak'

When I run all three above queries on the server with lower version than the server who owns backup file, again

I got the same error: “The media family on device 'C:\dbcheck.bak' is incorrectly formed. SQL Server cannot process this media family”

Test3:  Corrupts the backup and try to restore the database on same and lower versions

1. Take backup on any sql version
2. Corrupt the backup by opening them in notepad and delete some characters (I took backup of 10 Mb size database)
3. Try to restore on same and lower versions

I got error: “The file on device 'C:\dbcheck.bak' is not a valid Microsoft Tape Format backup set.”

So we confirmed (CONCLUSION)

1. If backup is correct and one is trying to restore on lower version or backup is done using third party toll like lite speed red gate.

Error: The media family on device 'C:\dbcheck.bak' is incorrectly formed. SQL Server cannot process this media family

2. If backup is corrupt :

Error: The file on device 'C:\dbcheck.bak' is not a valid Microsoft Tape Format backup set.”

Note: SQL server doesn’t support restore from higher to lower version.