Shadow copies are where restore points actually live
System Protection reports a percentage, vssadmin reports the truth. Reading the real figure and capping it without losing every restore point.
A drive can be full while every folder you can open adds up to far less. Shadow copies are one of the main reasons. They are block level snapshots kept by the Volume Shadow Copy Service, they back System Restore and the Previous Versions tab, and they live in a place Explorer will not show you.
The real figure, which Settings does not show
# Elevated prompt. The only honest answer.
vssadmin list shadowstorage
# The individual snapshots, oldest first
vssadmin list shadowsThe output gives three numbers per volume: used, allocated and maximum. Used is what is on the disk today, allocated is what has been claimed, and maximum is the ceiling the service will grow to. The System Protection dialog shows a percentage of the drive, which is the maximum rather than the current use, and that is the mismatch behind most of the confusion.
Where the space physically sits
Inside System Volume Information at the root of each protected drive, which is why that folder can be enormous and unreadable at the same time. It has its own page: System Volume Information.
Capping it instead of deleting everything
# Elevated. Sets a real ceiling for C:
vssadmin resize shadowstorage /for=C: /on=C: /maxsize=10GB
# A percentage works too
vssadmin resize shadowstorage /for=C: /on=C: /maxsize=5%Resizing down deletes the oldest snapshots to fit the new ceiling and keeps the newest, which is almost always what you want. Setting a ceiling once is better than deleting everything each time the drive fills, because protection turns itself back on and starts again.
Deleting them, in increasing order of regret
| Command | What goes |
|---|---|
vssadmin delete shadows /for=C: /oldest | The single oldest snapshot |
vssadmin delete shadows /for=C: /all | Every snapshot on C, including today's |
| Disk Cleanup, More Options, System Restore | All but the most recent restore point |
| Turning off System Protection | Everything, and no new ones are made |
The Disk Cleanup route is the one to reach for by default: it keeps the most recent point, so the machine still has somewhere to fall back to. Turning protection off entirely is the version people regret, and it is covered alongside the settings in System Restore and how much it takes.
Previous Versions, which is the same data
Right click a file, Properties, Previous Versions. Every entry there comes from a shadow copy. Deleting snapshots empties that tab, which is the cost people do not associate with the command they ran.
Common questions
How do I see how much space shadow copies use?
Run vssadmin list shadowstorage from an elevated prompt. It reports used, allocated and maximum space per volume. The percentage in System Protection is the maximum, not what is currently in use.
Is it safe to delete shadow copies?
It frees real space and removes your restore points and the Previous Versions history for those files. Resizing the storage with vssadmin resize shadowstorage keeps the newest snapshots and drops the oldest, which is usually the better trade.
Where are shadow copies stored?
In the System Volume Information folder at the root of each protected drive. Explorer cannot open it even as an administrator, which is why the space appears to belong to nothing.
Why does vssadmin say no items found?
Either nothing has created a snapshot on that volume, or the prompt is not elevated. Without elevation the command reports an empty result rather than an access error.