The C drive is red, updates are failing, and a video title is promising you 7 GB from reserved storage. That 7 GB is real — but on most PCs it is not even the biggest safe win available, and grabbing it first teaches you nothing about why the drive filled. Here is the honest order: biggest and safest first, the reserve in its proper place.
Every full drive has a story, and Storage settings already tells it. Before deleting anything, open Settings, System, Storage and read the category bars. Then work this order: temporary files and update leftovers, the hibernation file if you never hibernate, the component store the supported way, your own large files — and reserved storage last, because it is the one item on the list that is doing a job for you. Skipping straight to the reserve is like selling the spare tyre because the fuel tank is empty.
👆 Read your own breakdown first. On many PCs, Temporary files alone beat the entire reserved storage figure.
This is the free money: caches and the remains of old updates that Windows itself offers to remove.
After a feature update this page also offers the previous Windows installation — often 10 GB or more — once you are sure you will not roll back.
If you never use Hibernate, its file is pure cost. hiberfil.sys is sized at roughly 40 percent of your RAM — on a 16 GB machine that is over 6 GB, rivalling the reserve itself.
powercfg /hibernate offKnow the side effect honestly: turning hibernation off also disables Fast Startup, which borrows the same file. If you love Fast Startup, keep the file and take your gigabytes elsewhere.
The component store grows with every update and tempts people into deleting it by hand. Never do that. The supported cleanup analyses first and removes only superseded components.
DISM /Online /Cleanup-Image /AnalyzeComponentStore to see the real size and whether cleanup is recommendedDISM /Online /Cleanup-Image /StartComponentCleanupThis routinely returns several gigabytes on an older install, with zero risk to servicing. The dedicated WinSxS page in this series covers ResetBase and its one-way trade-off.
After the steps above, many drives no longer need the reserve touched at all. If yours is still desperate — typically a 64 GB or 128 GB device — then take the final step with open eyes.
DISM /Online /Get-ReservedStorageStateDISM /Online /Set-ReservedStorageState /State:DisabledYou have now spent the safety margin, so adopt the manual rule: keep 10 to 15 GB free yourself, or switch the reserve back on before feature updates.
Watch the video for the reserved storage step in this order — and the Storage pages every fix here starts from.
▶️ Watch Full VideoIt depends on the PC. Windows Update Cleanup after a feature update and switching off an unused hibernation file each beat the 7 GB reserve on many machines. Read your Storage breakdown and take the biggest first.
Yes, through the Temporary files cleanup page, once you are certain you will not roll back to the old version. It is commonly 10 GB or more after a feature update and cannot be removed by hand safely.
Something is actively writing — update caches, an app cache, logs or sync folders. Open the Storage breakdown again and compare categories; the one that grew is your culprit, not reserved storage.