Quick fix: System Restore allocates a percentage of drive space for restore points (default 5–10%). On large drives, that’s 25+ GB silently consumed. Open System Properties → System Protection → Configure. Set Max Usage slider to 2–5%. Older points beyond the limit get deleted automatically.

WizTree shows C:\System Volume Information consuming 20–50 GB. That folder holds System Restore points and Volume Shadow Copies. By default, Windows allocates a percentage of drive space proportional to drive size — on a 1 TB drive, that’s 50–100 GB. Capping max usage recovers the space.

Symptom: System Restore points and shadow copies consume 20+ GB of C: drive without obvious indication.
Affects: Windows 11 (and Windows 10) with System Protection enabled.
Fix time: ~5 minutes.

What causes this

System Restore creates snapshots of system files and registry on schedule and before major changes (Windows Updates, driver installs). Each snapshot can be 500 MB–5 GB. Windows allocates a Max Usage percentage of drive space; old snapshots are deleted only when the cap is reached.

On a 1 TB drive with 5% cap, Windows can hold up to 50 GB of restore points. Volume Shadow Copies (separate from System Restore but uses the same storage) add to this. Both live in the hidden System Volume Information folder.

Method 1: Set Max Usage limit via System Properties

The standard route.

Press Win + R, type systempropertiesprotection, press Enter.
System Properties opens on the System Protection tab.
Find your C: drive. Click Configure.
Under Disk Space Usage: drag Max Usage slider.
- 2–3% — modest. Keeps a few restore points.
- 5–10% — comfortable. Default for most installs.
- 15–20% — generous. Useful for development PCs with frequent driver changes.
The dialog shows Current Usage. If above the new Max, Windows trims by deleting oldest points until under cap.
Click Apply → OK.
Optionally click Delete button to remove all current restore points (saves all current space; you lose ability to revert to past states).

This is the canonical fix.

Method 2: View and manage shadow copy storage

For more detail on what’s using space.

Open Terminal (Admin).
Check shadow storage:
```
vssadmin list shadowstorage
```
Shows allocated and current size per drive.
List actual shadow copies:
```
vssadmin list shadows
```
Each entry is a restore point or backup.
Set explicit storage cap:
```
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=10GB
```
Caps at 10 GB. Older shadow copies that don’t fit are deleted.
To delete all shadow copies:
```
vssadmin delete shadows /For=C: /all
```
Caution: removes ability to restore.
For deleting specific shadow copy: vssadmin delete shadows /Shadow={GUID} using GUID from list.

This is the right path for granular control.

Method 3: Disable System Protection entirely

For users who don’t use System Restore.

Open System Properties → System Protection → Configure (for C:).
Pick Disable system protection.
Click Apply. Existing restore points are deleted; space is recovered.
Trade-off: no protection against system changes. Windows Update, driver installs etc. no longer create automatic restore points.
For partial protection: keep enabled with 2–3% cap for the C: drive only. Skip protection for data-only drives.
For backup-first users: full disk image backups (Macrium Reflect, Veeam Free) replace System Restore with more comprehensive protection. Disable System Restore if you have reliable image backups.
To re-enable later: System Properties → System Protection → Configure → Turn on system protection.

This is the right path for backup-disciplined users.

How to verify the fix worked

Re-check C: free space. Should match the freed GB.
Run vssadmin list shadowstorage. Used Shadow Copy Storage Space now matches your new cap.
WizTree shows reduced System Volume Information folder size.

If none of these work

If shadow copies don’t shrink despite cap change: Resize doesn’t auto-delete: Windows respects new cap for future, but doesn’t always immediately purge existing. Run vssadmin delete shadows /For=C: /oldest repeatedly until under cap. Third-party backup software: Acronis, Veeam, or other backup tools use VSS for their own snapshots. Check those tools’ settings for their own retention. For PCs with disk corruption: run chkdsk C: /f. VSS data can become inconsistent and use unexpected space. For PCs that need granular control beyond Settings: vssadmin commands provide full programmatic control. Use in scheduled tasks for ongoing maintenance. For Hyper-V users: virtual machine checkpoints share VSS infrastructure with System Restore. Old VM checkpoints inflate System Volume Information. Manage via Hyper-V Manager → checkpoints.

Bottom line: System Protection allocates 5–10% of drive size for restore points. Lower Max Usage in System Properties → System Protection → Configure. Use vssadmin for granular VSS storage management.