My Father recently purchased an HP SimpleSave Drive and wanted to disable the Auto Backup feature. After searching HP's site and not finding anything useful, he called their phone support. The tech told him if he wanted to use it as a stand alone drive he would have to delete All of the HP files. Then if he wanted to use the SimpleSave software to back up drive later on, he was told he would have to go to HP's site and down load the App again.
If you still want the option to use the backup feature of the drive, but do not want it automatically start backing up as soon as you attach it, there is a much simpler solution. You can just create a folder (such as 'HP SimpleSave') and drag all the (HP) files into that folder. That way you can use the drive as a big USB drive, but also have the option to click on the folder, then click the SimpleSave file (to launch the app) and away you go.