Hi,
But I can't save it to the computer as a .WAV or .mp3 . And I can't save it on the external drive either (BTW what's a SGU file & should I be saving that as well as .mp4?)
.SGU is just a regular Band-in-a-Box song file. You need to save your songs as .SGU by going to File | Save, then you can open them later via File | Open. When you are finished creating a song (entering chords etc.), you might then choose to render/export your song as a .wav audio file or compressed audio file like .mp4 for whatever reason (maybe to upload to a website, import to a other software, etc.) This file cannot be opened back up into Band-in-a-Box to continue to edit. Well, you *could* import the .wav file to the audio track but that's different. You need to still open the .SGU (or .MGU) file to be able to edit the chord symbols, change the style, add RealTracks, etc.
You should install the latest update patch for your version - find it here:
https://www.pgmusic.com/support_windowsupdates.htmFor example, for 2017 it's build 471.
If you are still having problems, choose one thing that doesn't seem to be working, and describe specifically what happens when you do it.