• Windows
  • Backups

File History keeps every version until the drive is full

The default is to keep versions forever, and it copies whole files rather than differences. The two settings that decide how fast it grows.

5 min read

File History is the closest thing Windows has to a set and forget backup, and the default settings are chosen so that it never throws away something you might want. The consequence is a backup drive that fills, then stops backing up, usually without anybody noticing for months.

Two settings decide everything

SettingDefaultWhat it means for space
Save copies of filesEvery hourTwelve chances a day to store a new version
Keep saved versionsForeverNothing is ever removed automatically

Both live in Control Panel, File History, Advanced settings. Changing Keep saved versions to Until space is needed is the single change that turns a drive that fills into one that does not.

It copies whole files, not differences

Each version is a complete copy of the file at that moment. A 40 MB presentation edited once an hour for a working day is 320 MB of history by the evening. This is the detail that makes File History behave so differently from a backup tool that stores changes only, and it is why large files matter more than many files.

# What the backup is holding, per user, on the backup drive
$root = 'E:\FileHistory'
Get-ChildItem $root -Directory -EA SilentlyContinue | ForEach-Object {
  $s = (Get-ChildItem $_.FullName -Recurse -Force -File -EA SilentlyContinue |
        Measure-Object Length -Sum).Sum
  [PSCustomObject]@{ GB = [math]::Round($s/1GB,2); Path = $_.FullName }
} | Sort-Object GB -Descending

Clearing old versions properly

# Keeps the most recent version of everything, removes the rest
FhManagew.exe -cleanup 0

# Or remove versions older than 90 days
FhManagew.exe -cleanup 90

The Control Panel route is Advanced settings, Clean up versions, which offers the same choices in a dialog. Both are far better than deleting folders inside FileHistory by hand, which leaves the catalogue describing versions that are no longer there.

What it is actually protecting

By default: Libraries, Desktop, Contacts and Favourites. Not Program Files, not the system, and not anything you have stored outside those folders. If the point of the exercise is to be able to rebuild the machine rather than recover a document, that is a system image instead, and the two are frequently confused.

For versions of files on the internal drive rather than a backup drive, the mechanism is shadow copies, which is separate storage with a separate ceiling.

Common questions

Why is File History using so much space?

Because the default is to keep every version forever, and each version is a whole copy of the file rather than only the changes. A large document edited hourly produces a new full copy each time.

How do I delete old File History versions?

Run FhManagew.exe -cleanup 0 to keep only the newest version of each file, or pass a number of days such as -cleanup 90. Control Panel, File History, Advanced settings, Clean up versions does the same.

What does Keep saved versions until space is needed do?

It lets File History remove its own oldest versions as the backup drive fills, rather than stopping when it runs out. It is the setting that prevents a full backup drive.

Does File History back up my whole PC?

No. By default it covers Libraries, Desktop, Contacts and Favourites. Rebuilding a whole machine needs a system image, which is a different tool.

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