Software · guide

How to backup your computer, and against what exactly

By Alberto Gulotta · Updated 30 September 2026 · 9 min read

The question how to backup your computer has no single answer, and not because the subject is complicated. It is because “backup” is one word covering at least four different jobs, and a tool that answers one of them may not answer the others.

So the useful first question is not which software. It is which disaster.

That table is the whole of this guide, and the fourth row is the one worth sitting with. The limit is not in the software; it is in anything kept next to the machine it protects.

With the disasters separated, the tools become easy to place.

Microsoft’s help page files all three under “Backup tools”, and only two of them copy your documents. A restore point will not bring back a deleted photograph. Microsoft is clear about what System Protection is for — reverting after “software malfunctions, driver problems, or other system errors” — and that is a real and useful job. It is just not this one.

Windows Backup is worth reading carefully too, because its shape follows from its purpose. It requires a Microsoft account and stores what it collects with that account, which is exactly right for the job it was built for — walking up to a new PC and finding your things there. For my drive died and I need last Tuesday’s spreadsheet, the answer is File History, which restores previous versions of your files; the folders Windows Backup syncs to OneDrive also have the 30 days described in the table above.

On the Mac side, the size recommendation connects to another line on Apple’s page: “The oldest backups are deleted when your backup disk is full.” And keeping other files on the backup drive puts your working copy and your safety copy on one device. Apple’s one exception, for advanced users, is a separate APFS volume for those files — on the same device.

An external drive plugged in once a week, with either built-in tool pointed at it, already answers the first two cases in the table.

Apart from a final list of other guides, the guides below take it three ways: before a drive fails, phones, and the day it all matters — because a backup nobody has ever restored from is a belief rather than a fact.

Not covered here. It will not sell you backup software. Windows and macOS both ship tools for the cases above.

It will not tell you a restore point is a backup of your files. Microsoft describes what it is for, and a deleted file is not on the list.

And it will not pretend an external drive is enough on its own. While it sits next to the machine it is protecting, it answers two of the four cases at most. What holds instead is simple: the description of each Windows tool is Microsoft’s and the Time Machine recommendations are Apple’s, with the dates they were read.