I'm thinking of using the BB password keeper. and on the tour it has a random password generator if you clean your phone from time to time as i do. like now I'm thinking of going to 4.19 O/S will this hold my passwords if install a different OS or will the ones it made will lost on reinstall.
thanks

As long as you check the option to backup your device before performing the upgrade all your passwords should be restored on the new device.

Wirelessly posted

On OS upgrades and device switches, I have never lost password keeper data.

I'm still a belts and suspenders guy though. I have previous daily backup files. If you don't, I would do a manual backup beforehand, in addition to the backup that DM does automatically in the upgrade/switch process, just in case.