I have to admit to never doing backups of my system and I recently had corrupt file problems on Windows 10. Never having done them, I'd like advice please on how and when best to do backups.
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Only you can answer that.
In the same way as people are often asked how much of the work are you willing to lose then re-do? For example: Are you willing to spend couple of weeks typing up a full length novel, only to lose the whole novel due to corruption file system, so don't mind having to start again from the beginning (which would take you another two weeks)? Or do you prefer to back up the file at the end of every day, that way, when you found out the novel is corrupted, you don't mind having to re-do yesterday's work using the backed up file, which thankfully contains the past week's work still saved?
So when best to do backups depends on how often you use the computer, and how often you made any changes:
If you hardly turn on your computer for a few hours, every few days, and mainly just do photographic retouching, you could back up every week or something like that.
But if you always turn it on for hours after hours, all day, every day, and do a lot of downloading then installing and uninstalling lot of apps and other software, then better back up at the end of every day. (I would strongly recommend manually back up before installing, and back up again if you plan to install yet another software, same with backing up before uninstalling.)
You can answer your own question by knowing how often do your computer's files gets changed? Would you rather spend some minutes trying to resort a computer that worked fine until yesterday or spend hours trying to resort a computer, that for all you know, may have worked find last month, so you can't be sure if it was this week or last week that it got its files corrupted?