Project, to my knowledge, will not automatically delete tasks.Crash
might be by Project, or maybe something else on your computer. Hard to
really know what happened when crashes involved.
Could be your file is corrupted and since a crash involved, perhaps the
crash contributed to that. To deal with a corrupted file, see
http://project.mvps.org/faqs.htm#Handling_project_file_corruption_and/or_bloat
Far as I know, Project will not make backups automatically. In Menu:
Tools/Options, Tab: Save you can set Auto Save options.
We have two automatic backups. Over the years, I've lost too many files
and made too many mistakes that were solved by going back to previous
versions. Hence we prefer backup strategy that involve lots of older
versions and lots of automation (so we don't get opportunity to forget).
: we tend to store files on Apple Mac file systems and use Apple's Time
Machine backup to an external drive. Surely an equivalent software on
Windows but we haven't bothered to look.
: we work on the files locally, but automatically sync the files from
the PC up into SharePoint. SharePoint holds a long history of the files.
Which means we can easily go back to the version we had "last Tuesday"
and start again from there. This is particularly valuable during the
start-up of project modelling.
If you don't have above-then every so often (once a day is often about
right), zip all the project files into an archive.
--rms
www.rmschneider.com