Every drive has a folder you are not allowed to open
The hidden folder on each volume, what Windows keeps in it, and why access is denied even to an administrator.
Turn on hidden and system files and every drive has a System Volume Information folder that refuses to open, even for an administrator. That refusal is deliberate and the folder is worth understanding rather than fighting.
What is in it
| Content | What it is |
|---|---|
| Shadow copies | System Restore points and backup snapshots |
| Distributed Link Tracking | How Windows follows moved files |
| Indexing data | Search index fragments for that volume |
| Storage Sense state | What has been cleaned and when |
| Dedup store | On volumes with deduplication enabled |
Why access is denied
The folder is owned by SYSTEM and its permissions deliberately exclude administrators. That is not an oversight: the contents include shadow copy data that must not be modified while the volume service is using it, and giving a user write access there is a genuine way to lose restore points and corrupt backups.
Seeing how much it uses
vssadmin list shadowstorage
# Needs an administrator prompt. Shows used, allocated and maximum per volume.That is the supported way to find out what the folder costs, and it reports the number that matters: the cap, which is what explains a large figure.
Making it smaller
Not by touching the folder. Reduce it by capping or clearing System Restore, which owns most of the space, and that is done in System Properties, System Protection, as covered in System Restore and shadow copies.
On an external drive
External drives get one too, holding restore data if the drive was ever protected and indexing data if it was indexed. Turning off System Restore for that drive and excluding it from indexing removes the reason for it to grow, which is worth doing on a drive used purely for archives.
Common questions
What is the System Volume Information folder?
A hidden folder on every volume holding shadow copies, distributed link tracking data, indexing fragments and Storage Sense state. It is owned by SYSTEM and deliberately inaccessible.
Why is access denied to System Volume Information?
Because its permissions exclude administrators on purpose. The contents include shadow copy data that must not be modified while the volume service is using it.
How much space does System Volume Information use?
Mostly whatever System Restore's cap allows. Run vssadmin list shadowstorage in an administrator prompt to see used, allocated and maximum per volume.
Can I delete System Volume Information?
No, and you should not try. Reduce it by capping or clearing System Restore in System Properties, System Protection, which owns most of the space.