Free Up SSD Space Safely in Windows 10 and 11: Hibernation, Pagefile, Restore and Reserved Storage

The short verdict​

Hiberfil.sys: the optional one​

Microsoft documents the hibernation file as a hidden system file in the root of the Windows drive. Without it, the PC can't hibernate. Hibernation files come in two types, full and reduced. I'm using Microsoft's power-states documentation for the next two points.

• Full file: supports hibernation, hybrid sleep and Fast Startup. It defaults to 40% of physical RAM.
• Reduced file: supports Fast Startup only. It defaults to 20% of RAM.

Those percentages are defaults, not fixed sizes. Your actual file depends on your RAM and any custom size set on the machine.

The commands, run from an elevated terminal:

1. powercfg /hibernate off removes the file. It also disables hibernation, and hybrid sleep and Fast Startup go with it. Microsoft's troubleshooting page warns you can lose data if hibernation is unavailable and power fails while hybrid sleep is on.
2. powercfg /hibernate /type reduced keeps Fast Startup and shrinks the file.
3. If the reduced command fails because the file has a custom size, Microsoft says to run powercfg /hibernate /size 0 first, then retry the reduced command.
4. powercfg /a shows which sleep states your system supports, so you can confirm the result.

Laptop users should think twice before removing it, since hibernation saves a session without drawing battery. A desktop that never hibernates is the clearest case for reclaiming the space. The article's claim that a fast SSD makes hibernation unnecessary is a judgment call, not a Microsoft finding. Fast Startup speeds up boot, and it is also the reason the file exists on PCs whose owners never touch the Hibernate button.

Pagefile.sys: leave it alone​

Microsoft's page-file documentation explains why plenty of RAM doesn't make the file redundant. The page file extends the system commit limit, which is physical memory plus all page files combined. If the commit charge reaches that limit, Microsoft says the system and processes may freeze, crash or malfunction.

Microsoft does concede that on machines with very large RAM, a page file might not be needed to cover peak commit demand. It adds that a page file or a dedicated dump file may still be needed for crash dumps.

System-managed page files grow when the commit charge hits 90% of the commit limit. The documented growth cap is three times physical memory or 4 GB, whichever is larger. It is also limited to one-eighth of the volume, and free disk space has to be available. In practice, the system-managed setting uses what it needs rather than a fixed oversized block. Manual tuning is an expert move, and it's rarely worth it for a few gigabytes.

System Restore: cap it, don't kill it​

System Restore uses restore points that capture system files, installed apps, the registry and settings. It can undo a bad driver or software change without touching personal files.

Microsoft's current System Protection page contains a detail the original piece glosses over: the feature is not enabled by default, though Microsoft recommends turning it on. Many PCs may not be accumulating restore points at all. Check before assuming it's the culprit.

To check or cap it:

1. Search Start for "Create a restore point", or press Win+R and run systempropertiesprotection.exe.
2. Select the system drive and choose Configure.
3. Turn on protection if you want it, and set the maximum disk usage slider.
4. Select Apply.

The slider sets a ceiling, not an immediate allocation. When it fills, older points are removed to make room.

To roll back, run rstrui.exe from Windows. From the Windows Recovery Environment, go to Troubleshoot > Advanced options > System Restore. On an encrypted device, Microsoft says you'll need your BitLocker recovery key.

Point-in-time restore: newer, shorter, riskier​

This is where the original article needs correcting. It says Point-in-time restore requires Windows 11 24H2 or later. Microsoft's current support page doesn't say that. It lists the feature as applying to Windows 11 and Windows 10, and the defaults depend on management status and drive size.

What Microsoft does document:

• Schedule: snapshots about every 24 hours, kept for up to 72 hours.
• Space: the maximum usage limit defaults to 2% of the disk. Microsoft says space isn't reserved in advance.
• Default state: it is already on by default for unmanaged devices. On IT-managed devices it is currently off by default, and Microsoft says it will be on by default starting with Windows 11 version 26H2.
• Drive size: for default enablement, the OS volume must be at least 200 GB. Smaller volumes can turn it on manually.
• Configuration: frequency, retention and the usage limit are configurable only on Enterprise editions.
• Where to find it: Settings > System > Recovery > Point-in-time restore > View or edit. Only local admins can see or change it.

How it differs from System Restore​

Microsoft suggests trying Point-in-time restore first when it's available. It points you to System Restore for problems older than 72 hours, or when Point-in-time restore isn't available. So the two aren't really duplicates, and the "overlap" framing is only partly fair.

The catch​

A restore reverts the whole system drive. Anything you changed after the snapshot is lost, including new files, apps, settings, passwords, certificates and keys. OneDrive and other cloud files aren't affected. Other drives aren't restored. Microsoft recommends free space at least equal to the total size of the restore points. It also warns that a restore may roll back recent security updates, so install the latest updates afterward.

Recovery runs from WinRE: Troubleshoot > Point-in-time restore. Have the BitLocker key ready, and don't power off mid-restore. Microsoft recommends plugging in a laptop first.

Because the snapshots live on the same drive, they are not a backup. If you already run real backups, this is the easiest safety net to give up. If you often break your own PC, 2% of a drive buys you a useful undo button.

Reserved Storage: not a locked vault​

Reserved Storage is not an undeletable file, as the original article rightly says. Microsoft describes it as space set aside for temporary files, caches and update servicing. When the drive runs low, Windows can release it to other processes, including Windows Update.

You can check and change the state from an elevated prompt:

• DISM.exe /Online /Get-ReservedStorageState
• DISM.exe /Online /Set-ReservedStorageState /State:Disabled
• Swap in /State:Enabled to turn it back on.

The PowerShell equivalents are Get-WindowsReservedStorageState and Set-WindowsReservedStorageState. These work only on online images. If the reserve is in use, Windows may refuse with an error, and Microsoft's guidance is to wait for servicing to finish and try again.

Disabling it can make free space look larger, but you lose the buffer that makes updates less likely to fail. A NinjaOne guide warns that low space with the reserve off can cause update failures such as error 0x80070070. Treat it as an advanced, reversible tweak, not a routine cleanup step.

A sensible cleanup order​

1. Check what's actually using space before changing anything. The page file and hibernation file are hidden system files, and the restore features only use up to their caps.
2. Shrink hibernation to reduced mode, or remove it on a desktop you never hibernate.
3. Put a modest cap on System Restore, if it's enabled at all.
4. Decide on Point-in-time restore based on whether you have real backups.
5. Leave the page file system-managed.
6. Leave Reserved Storage alone unless you're truly out of room.

None of these features backs up your personal files. System Restore skips them, and Point-in-time restore can erase recent changes to them. If you're cutting safety nets to make room for photos, set up an external or cloud backup first.