How to Free Up Gigabytes of Disk Space with Storage Sense & Disk Cleanup

When your local drive C: turns red and starts throwing "Low Disk Space" warnings, your system cannot write temporary files, create virtual memory swap pages, or install critical security updates. You do not need third-party registry or cleaner apps. Windows has two built-in storage engines designed specifically to purge safe caches.

Step 1: Launch Elevated Disk Cleanup (System Files Mode)

Running Disk Cleanup normally only checks your user-level temporary files (often saving less than 500 MB). To unlock the real storage hogs—such as previous Windows installations and old update packages—you must launch it in administrator mode:

1. Press Win + R, type cleanmgr, and press Enter.
2. When the window opens, click the button labeled "Clean up system files".
3. Windows will rescan the drive with administrative access.

Step 2: What to Check (and What to Avoid)

In the elevated list, check the following items to safely recover 10 GB to 30 GB+:

• Windows Update Cleanup (3 GB – 15 GB): Retains only the latest versions of updated files and discards superseded patches.
• Previous Windows installation(s) [Windows.old] (15 GB – 30 GB): Generated whenever Windows updates to a new major feature release (like 24H2). If your system is stable, this is safe to delete.
• Temporary Windows Installation Files: Leftover installation packages.
• Delivery Optimization Files: Downloaded update caches shared across local network PCs.

Step 3: Enable Automated Storage Sense in Windows 11

To ensure your C: drive never fills up unexpectedly again, activate Storage Sense:

1. Open Windows Settings (Win + I).
2. Navigate to System > Storage.
3. Toggle Storage Sense to ON.
4. Click into Storage Sense to configure automated cleanup cadence (e.g. "Run every week" or "During low free disk space").

Step 4: Reduce or Disable Hibernation (hiberfil.sys)

If you are on a desktop PC that you never put into deep hibernation, the Windows hibernation file reserves 75% of your total RAM capacity on drive C: (e.g. 24 GB of space on a 32 GB RAM machine!).

To reduce its size by 50% without disabling fast startup: