Q: forgotten backup encrypt password how do i get round that?

That is correct. If you have forgotten the password for an encrypted backup, your only alternative is to delete the backup and restore the iPhone to factory. You will not be able to use that backup, and without the passcode, you will not be able to turn of encryption. You have to delete the backup so that iTunes will allow you to backup to the computer again. The password is also saved in the backup. See this support document about encrypted backups. About encrypted backups in iTunes - Apple Support  As you see, one of the first statements in the support document, There is no way to recover your information or turn off Encrypt Backup if you lose or forget the password.