If I re-install Moodle will I loose all student data?
If I re-install a module will I loose all previous data?
If you keep the databases and just replace the Moodle files, then no, you won't lose any data. Same with any module.
If you delete the database then you will lose all your data, yes.
If you delete the database then you will lose all your data, yes.
Thanks to you both. I'll try it.
Here is the info on how to upgrade moodle files and keep student data and course data.