We often blame third-party apps or our growing pile of files when storage runs low, but Windows itself can quietly eat up far more space than you’d expect. If your system drive keeps filling up unexpectedly, built-in Windows features are often the real cause. Here’s how to reclaim gigabytes of storage in just minutes.
System Restore
Whenever you face an unsolvable problem on Windows, System Restore can be a lifesaver, letting you roll back to a previous state. The catch is that Windows automatically creates restore points before updates, driver installations, and other system changes. It keeps adding new points until the allocated storage fills up, at which point it deletes the oldest ones to make room.
To prevent this feature from using too much space, you can limit Windows to keep just two or three restore points. Type Create a restore point in the search bar and select the matching result. In the System Properties window, open the “System Protection” tab, select your system drive, and click “Configure.”
You can see how much space System Restore is currently using next to Current Usage. The Max Usage slider indicates the maximum amount of storage System Restore can consume—adjust it to limit the disk space Windows allocates to System Restore.
Reserved Storage
Windows reserves part of your drive as Reserved Storage to ensure updates, apps, and temporary files have sufficient space to operate correctly and prevent update failures. By default, this consumes 7–10 GB and can grow over time. Because this reserved space helps Windows install updates smoothly and maintain performance, you shouldn’t disable it.
However, if you’re extremely low on storage and need a few extra gigabytes, you can temporarily free it up. To check how much space Reserved Storage is using, go to Settings > System > Storage, then click Show More Categories > System & Reserved.
Windows doesn’t provide a direct toggle in Settings to disable this feature, so you’ll need to use PowerShell. Type PowerShell in Windows Search, right-click the app, and select “Run as Administrator.” Then run the following command to free up the reserved storage:
Set-WindowsReservedStorageState -State Disabled
Hibernation File (hiberfil.sys)
When was the last time you actually used your PC’s hibernate feature? If your answer is “never” or “a long time ago,” you could be wasting several gigabytes of storage—roughly equal to your installed RAM. Hibernate preserves your open apps and documents so you can resume exactly where you left off, but if you don’t use it, you can reclaim that disk space.
To check how much space this feature is using, you’ll first need to unhide the hiberfil.sys file. Go to the “View” tab, click Show > Hidden Items.
Then, click the three horizontal dots, select “Options,” go to the “View” tab, and uncheck “Hide protected operating system files (Recommended).” Then click “Apply,” followed by “OK.”
After that, right-click the “hiberfil.sys” file, choose “Properties,” and you’ll see the storage it occupies in gigabytes.
Then, use Command Prompt to disable hibernation and delete the hiberfil.sys file. Type Command Prompt in the searchbar, right-click it, and select “Run as Administrator.” Then type:
powercfg /hibernate off Press Enter, restart your computer, and the hiberfil.sys file will be removed, freeing up valuable storage space.
Feature update rollback files (Windows.old)
Windows keeps a backup of your previous system state so you can roll back a problematic update. This backup is stored in the Windows.old folder and includes old system files, drivers, and settings—often taking up 10–30 GB or more. If your current update is running smoothly and you’re sure you won’t need to roll back, deleting this folder can free up significant space.
Although Windows automatically removes the Windows.old folder after about 10 days, you can delete it sooner if you’re low on storage. To do that, right-click the Start button, open “Settings,” go to System > Storage, click “Temporary Files,” check the box beside “Temporary Windows Installation Files,” and click “Remove Files.”
Keep in mind that deleting this folder only removes the built-in rollback option. If you ever need to roll back later, you can always do it through a manual installation.
Hyper-V virtualization
Have you ever used Hyper-V to spin up a virtual machine, test Linux, or experiment with development tools? If not, you can skip this point. But if you tried it once and never went back, the leftover virtual hard disks, snapshots, and configuration files could consume 10–50 GB, or more if you created multiple VMs or snapshots.
Also, removing a VM from Hyper-V Manager doesn’t always delete every related file. Make sure you properly delete any unused VMs from Hyper-V Manager, then manually check the default VM storage folders for leftover .vhdx files. Once everything is cleaned up, disable Hyper-V and other virtualization features from Windows Features to prevent unnecessary storage use.
Running out of storage isn’t always because you’ve installed too many apps or piled too many files. Windows quietly consumes large amounts of space for features most users never notice. The good news is that this storage drain isn’t hidden or irreversible—use the tips above to identify what’s eating up space, decide what you actually need, and reclaim several GBs.
