Quick fix: Open System Properties (Win + R, sysdm.cpl) → System Protection tab → select C: → Configure. Slide Max Usage to 10-15%. On a 500 GB drive this gives 50+ GB for restore points — enough to retain weeks of history.

Windows’ default System Protection allocation is small — about 1-3% of drive space, often just 5-10 GB. Active drives fill this quickly, and Windows evicts older restore points to make room for new ones. Increasing the allocation extends retention so you have older points available when you need them.

Symptom: System restore points expire quickly; want longer history of available restore points.
Affects: Windows 11 (and Windows 10) System Protection.
Fix time: ~5 minutes.

What causes this

Volume Shadow Copy Service (VSS) stores restore points in C:\System Volume Information. The space allocated to this folder is capped by a percentage setting. When new restore points exceed the cap, VSS evicts older ones. On active drives with frequent file changes, each restore point contains many delta changes from the previous one — even a few weeks of activity can fill a 5 GB allocation.

Method 1: Increase via System Protection UI

The standard approach.

Press Win + R, type sysdm.cpl, press Enter.
Switch to the System Protection tab.
Select your System (C:) drive (or any drive you want to protect). Click Configure.
Confirm Turn on system protection is selected.
Move the Max Usage slider to your desired percentage. Recommendations:
- 500 GB drive: 10% = 50 GB
- 1 TB drive: 5-10% = 50-100 GB
- 256 GB drive: at least 20 GB (about 8%)
- 2 TB+ drive: 3-5% is plenty
The slider shows the allocated space in GB on the right.
Click Apply → OK.
Existing restore points are preserved. New ones now have more headroom before eviction kicks in.

10% is comfortable for most users.

Method 2: Use vssadmin to set allocation precisely

For scripted setup or when you want a specific GB value.

Open Terminal (Admin).
Check current shadow storage allocation:
```
vssadmin list shadowstorage
```
Shows allocated, used, and maximum for each volume.
Resize the max allocation:
```
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=50GB
```
The /For=C: specifies the volume being protected; /On=C: specifies where shadow data is stored (typically the same drive).
Verify with vssadmin list shadowstorage — new max appears.
For Unlimited (use full disk space available):
```
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=UNBOUNDED
```
Not recommended for active drives — VSS will consume more space than you expect.

This is the precise control. Use exact GB values for predictable space usage.

Method 3: Configure shadow storage on a separate drive

For systems with a secondary drive — store restore points there to keep C: lean.

Confirm you have a second drive (D:, E:, etc.) with at least 50 GB free.
Open Terminal (Admin).

Set the shadow storage location for C: to be on D:

vssadmin resize shadowstorage /For=C: /On=D: /MaxSize=100GB

Restore points for C: are now stored on D:. C: drive space isn’t consumed.
Important: if D: drive becomes unavailable (USB drive unplugged, second drive fails), restore points are inaccessible. Use only with always-attached internal drives.

To revert to storing on C: itself:

vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=50GB

This is useful on PCs with a smaller SSD + larger HDD configuration. Keep restore points off the limited C: drive.

How to verify the fix worked

Open System Properties → System Protection → C: → Configure. Max Usage shows your set percentage.
Create a few test restore points (Create button). Each adds to allocation usage but doesn’t exceed the new max.
Run vssadmin list shadowstorage. Max appears as your set value; used grows as restore points accumulate.
Older restore points persist longer because the allocation has room.

If none of these work

If the allocation change doesn’t persist or restore points still vanish quickly, three causes apply. Group Policy override: corporate-managed PCs may enforce specific shadow storage settings. Check gpresult /h C:\gpresult.html for related policies. VSS service issue: ensure Volume Shadow Copy service is running. Open services.msc, find Volume Shadow Copy, set StartType to Manual (default). Drive too full: VSS aggressively evicts when overall drive space is low — keep at least 20% free space on the drive holding shadow storage. For chronic restore-point eviction, consider Macrium Reflect Free for full disk imaging as an alternative — uses separate storage and isn’t constrained by VSS allocation rules.

Bottom line: System restore allocation defaults too small — bump to 10-15% via System Protection UI or use vssadmin for precise control. More space = longer retention.