You missed the part about the feature being added in version 1.50 (v1.51 was a fast-follow version to correct a bug in v1.50 - so v1.51 is the first version which was not buggy which had this feature).

Save songs, user, and libraries separately now - upgrade - restore - then use the "all" (backup) once you have a version which supports it (after upgrade).

Just bought a montage 7 version 1.20.4 and want to backup the files before updating to 2.5, but i can't find "backup" in the options, i can only choose "performance" "library file" "user file" of ".mid file", what do i miss?

If you just purchased a MONTAGE 7, you likely have nothing to backup just yet.

You can check on data that is in your USER bank as follows:
Press [UTILITY]
Touch “Contents” > “Data Utility”
Here you will see various folders: Arp, Library, Live Set, Motion Seq, Performance, Song, and Waveform

You can touch each folder, in turn, to check its contents. Touch the “Montage” box to return to the top level.

The User Bank and Libraries of a new MONTAGE are completely unoccupied. As are the other folders, initially.
If you recorded any original Songs using the Performance Recorder be sure to save them to a USB drive as .mid Files (these are not saved to the User File)...

You can just go ahead and update your firmware to version 2.50.x... it will bring you entirely up-to-date.... adding over 700 new sounds, new effects, new features... the download includes a new Supplementary (new feature) Manual, and get the latest Data List Booklet from the global Yamaha.com MONTAGE product page (Downloads).

If you do have data in any of the folders, create a User File by touching the “Store/Save” box in column two, set the “Content Type” = User File... and Save a New User File to a USB stick.

To Jason and Bad Mister, thanks for your help, it's all clear now........i'll go updating version 2.5 this evening....