Dwindling Free Space Windows 10

mgrlvr

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Jan 19, 2026
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Hi! I am new to this forum.

Free space on my Windows 10 machine with 118 GB SSD has been an issue for the past several months. I had 8 GB of data stuck in my recycle bin. I resolved that issue about 4 days ago. I uninstalled Adobe Reader and reinstalled another version. Between those two actions, I was at 14.5 GB of free space on the C drive. The free space has been dwindling over the past four days to where I am now at 4 GB free space. I've not added anything to the machine. Why would I lose approximately 10 GB of free space without doing anything? I read something about hibernation taking up a large amount of space. What additional information do I need to post that will help the knowledgeable folks on the forum help me with my problem?

Thanks so much.

Pat
 

Solution
15.3 GB means the cap did change, but it’s still set too high for what you described as a “small cap” on a 128 GB SSD.
On a drive this size, I’d typically set System Restore to ~3–5 GB.

Step 1: Reduce the cap to 5 GB (recommended)​

GUI way​

  1. Win + RSystemPropertiesProtection
  2. Select C:Configure
  3. Move Max Usage down until it’s about 5 GB (or ~3 GB if you’re extremely tight)
  4. ApplyOK

Command line way (precise)​

Open Command Prompt (Admin) and run:
vssadmin Resize ShadowStorage /For=C: /On=C: /MaxSize=5GB
If Windows refuses because current usage is higher, do Step 2 first, then run the resize again...
With only 4.26 GB free, you’re in the “Windows may start malfunctioning / updates may fail” zone. The good news is your earlier numbers show VSS/Restore Points were a big contributor, but capping alone doesn’t immediately return space—you also have to remove older restore points and clear system caches.
Below is the safest “get space back fast” sequence.

Step 1 (fast, safe): Delete older restore points (keeps the most recent)​

This is the quickest way to claw back most of that ~9–10 GB VSS usage you saw.
  1. Start menu → type Disk Cleanup
  2. Right‑click Disk Cleanup → Run as administrator
  3. Select C:
  4. Click Clean up system files
  5. Go to More Options tab
  6. Under System Restore and Shadow Copies → click Clean up…
This keeps only the latest restore point and removes the older ones.
After that, reboot and re-check free space.

Step 2: Set the cap to a truly “small” value (3–5 GB)​

Right now you said Maximum shadow copy storage is 15.3 GB—that’s still large for a 128 GB SSD.
Run Command Prompt (Admin):
vssadmin Resize ShadowStorage /For=C: /On=C: /MaxSize=5GB
If Windows refuses because current “Used” is above 5 GB, do Step 1 first (cleanup), then run this again.

Step 3 (often a big win on 8 GB RAM): Disable Hibernate (if you don’t use it)​

On an 8 GB RAM system, this can free multiple GB immediately.
Command Prompt (Admin):
powercfg /h off
Note: This disables Hibernate and Fast Startup.

Step 4: Run Disk Cleanup (system files) selections that often recover several GB​

Repeat Disk Cleanup (Admin) → Clean up system files, then check items like:
  • Windows Update Cleanup
  • Delivery Optimization Files
  • Temporary files
  • Device driver packages (if offered)
(Do not check “Downloads” unless you’re sure.

Step 5 (don’t delete WinSxS manually): Component store cleanup​

Command Prompt (Admin):
Code:
DISM /Online /Cleanup-Image /AnalyzeComponentStore
DISM /Online /Cleanup-Image /StartComponentCleanup
This is the supported way to reduce WinSxS bloat.

After you do Steps 1–3, please post these 2 things​

1) The new output of:
vssadmin list shadowstorage
(Just the Used / Allocated / Maximum lines are enough.
2) Your new free space on C:.
If you do Step 1 (restore point cleanup) + Step 3 (hibernate off), you’ll very often jump from ~4 GB free to well over 10–15 GB free quickly.
 

It depends what Windows is calling a “PC backup” — there are two common things people mean, and the advice is different.

1) If you’re seeing “Previous Windows installation(s)” (Windows.old)​

This is not a “backup you created” — it’s the folder Windows keeps so you can roll back to the previous Windows build/version.
  • Pros of deleting: can free many GB quickly.
  • Con of deleting: you lose the ability to roll back to the prior Windows version/build using the built-in rollback option.
Rule of thumb: If your PC has been working fine since the last big update and you’re not planning to roll back, it’s usually OK to remove it—especially with only ~4 GB free.

2) If you mean Windows system image / “Backup and Restore (Windows 7)” backups

These are “complete PC backups” (system images / backup sets) and can be huge.
  • If they’re stored on C:: yes, deleting older ones can be a good idea (but keep at least one known-good recent backup).
  • If they’re stored on an external drive: you usually don’t need to delete them to fix C: space.
Best practice: Keep the most recent system image (or at least one you trust) and delete older ones only if you’re sure you won’t need them.

Quick question so I tell you the right “yes/no”​

Where exactly are you seeing that option?
  • In Disk Cleanup (a checkbox list)? If yes, what is the exact wording you see.
  • Or in Control Panel → Backup and Restore (Windows 7) → Manage space?
Reply with the exact wording (or a screenshot), and I’ll tell you which ones are safe to remove and how much space you’re likely to get back.
 

Excellent—that result is exactly what we wanted. Going from ~4 GB to ~10 GB free after capping Shadow Copy storage strongly confirms that System Restore/VSS was the main “space leak.”
That said, on a 128 GB SSD you’ll be a lot happier if you can get to 15–20 GB free so Windows Update and temp files don’t constantly push you back into the danger zone.

What to do next (safe + keeps restore points)​

1) Re-check VSS numbers (make sure it will stay controlled)​

Open Command Prompt (Admin) and run:
vssadmin list shadowstorage
You want to see:
  • Maximum5 GB
  • Used/Allocated at or below that, and not creeping upward endlessly anymore
If you paste those 3 lines here (Used/Allocated/Maximum), I’ll confirm it’s perfect.

2) Keep only the most recent restore point (optional, but often frees more)​

If you still need a few more GB and don’t mind losing older restore points:
  1. Disk Cleanup → right-click → Run as administrator
  2. Clean up system files
  3. More Options tab
  4. Under System Restore and Shadow CopiesClean up
This keeps the newest restore point.

3) Run Disk Cleanup (system files) for update leftovers​

Still in Disk Cleanup (admin), also check things like:
  • Windows Update Cleanup
  • Delivery Optimization Files
  • Temporary files
(Leave Downloads unchecked unless you’re sure.

4) Optional “big win” if you don’t use Hibernate (often several GB)​

powercfg /h off
This disables Hibernate/Fast Startup and removes hiberfil.sys.

Prevent it from happening again​

  • Leave System Restore ON but capped (you already did this).
  • Turn on Storage Sense: Settings → System → Storage → Configure Storage Sense (set it to run automatically).

Quick question​

After a reboot, does your free space stay around 10 GB, or does it start dropping again?
If it drops again, the next likely culprit is Delivery Optimization cache or Windows Update cleanup, and we can pinpoint it with one more TreeSize view of C:\ProgramData and C:\Windows\SoftwareDistribution.
 

Yes—rebooting is recommended after the changes you just made.

Why reboot helps​

  • Windows may not immediately release/reflect freed space until services restart.
  • It ensures the Volume Shadow Copy (VSS) and System Restore components re-initialize under the new 5 GB cap.
  • If Windows Update services were active (common), a reboot helps them settle and prevents “stuck” temp usage.

What to do​

  1. Close your programs and restart the PC (Start → Power → Restart).
  2. After restart, check:
    • This PC → Local Disk (C:) free space
    • (Optional) run in an Admin Command Prompt:
      vssadmin list shadowstorage

What you should expect​

  • Free space should be about the same or slightly better than before the reboot.
  • It should not continue dropping rapidly anymore now that VSS is capped.
If after reboot your free space starts falling again (e.g., you lose multiple GB over a day), tell me and we’ll check the next most common grower: Delivery Optimization cache and Windows Update temp files.
 

Can I stop for now and restart this conversation again tomorrow?
 

Yes, absolutely.
Go ahead and stop for now. When you come back tomorrow, just reply in this same thread and mention:
1) Your free space on C: (after the reboot, if you do reboot), and
2) The current output of (Admin Command Prompt):
vssadmin list shadowstorage
If the free space starts dropping again overnight, also tell me roughly how many GB it drops and over what time period.
We’ll pick up right where we left off.
 

Hi! I am new to this forum.

Free space on my Windows 10 machine with 118 GB SSD has been an issue for the past several months. I had 8 GB of data stuck in my recycle bin. I resolved that issue about 4 days ago. I uninstalled Adobe Reader and reinstalled another version. Between those two actions, I was at 14.5 GB of free space on the C drive. The free space has been dwindling over the past four days to where I am now at 4 GB free space. I've not added anything to the machine. Why would I lose approximately 10 GB of free space without doing anything? I read something about hibernation taking up a large amount of space. What additional information do I need to post that will help the knowledgeable folks on the forum help me with my problem?

Thanks so much.

Pat
This behavior is typically caused by Windows managing system storage in the background rather than user activity. Over several days, Windows Update can cache update files, System Restore can automatically create restore points, and the paging file can expand as memory demands change. On a 118 GB SSD, these system-managed files can easily consume 8–10 GB without any visible installs or downloads. Reviewing Storage Settings and running Disk Cleanup with system files enabled will usually identify and reclaim the space.
 

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