WinSxS Folder Huge? Don’t Delete It — Here’s How to Shrink It Safely

Your C: drive is almost full, so you start digging through File Explorer for whatever is eating your storage. Downloads? Maybe. Recycle Bin? Sure. And then you find this monster:

C:\Windows\WinSxS

Ten, twenty, thirty gigabytes or more. So naturally, your brain says: “Can I delete this?”

No. Don’t delete it, don’t start ripping files out of it by hand, and definitely don’t trust the forum post from 2012 where a guy says “worked for me.”

Prefer to watch instead of read? Here’s the full walkthrough — or skip it and keep reading below.

What Is the WinSxS Folder?

WinSxS stands for Windows Side-by-Side. In plain English, it’s the Windows component store — which, yes, doesn’t exactly clear things up.

Think of it as the parts warehouse Windows uses whenever something needs to be installed, repaired, rolled back, or serviced. It holds system components, update files, optional-feature files, and versions of files Windows may need later. It’s involved when Windows installs updates, when you add or remove Windows features, and when repair tools like DISM and SFC try to fix problems.

So it’s not a junk drawer. It can get big — but “big” doesn’t automatically mean “safe to delete.” That’s where people get into trouble.

Why It Looks So Huge

Right-click WinSxS, choose Properties, and the size can look terrifying. It’s also misleading.

WinSxS uses links to files that live elsewhere in Windows, so File Explorer counts some of the same files more than once. A folder that shows 20 or 30 GB doesn’t mean you can delete it and get 20 or 30 GB back. The amount you can actually recover is usually much smaller.

What Breaks If You Delete It

Best case: Windows stops you. Many of the files are protected, and you can’t delete them without taking ownership, changing permissions, or running a cleanup tool that promises miracles. If your cleanup plan requires fighting Windows inside C:\Windows, stop. That warning isn’t there for decoration.

Worst case: you succeed. And that’s where the fun begins. You can break Windows Update, optional feature installs, DISM, and SFC, or corrupt the component store itself.

The nasty part is that it may not fail right away. You delete something today, everything seems fine, and two weeks later Windows Update throws an error code that looks like a hexadecimal ransom note. (If that’s already happened to you, start here: Windows Update Keeps Failing? Do This Instead.)

Step 1: Clear the Real Space Hogs First

Most of the time, WinSxS isn’t your real problem — it’s just the scary Windows folder you noticed first. Before touching it, go to Start → Settings → System → Storage → Temporary files and let Windows scan. Read the list before checking boxes — especially Downloads, because Windows can’t tell an old installer from an important file you downloaded six months ago and forgot about.

Then check the usual suspects: Downloads, the Recycle Bin, old installers, games, phone backups, OneDrive folders, and that random desktop folder called “New Folder 7” that somehow holds 400 GB of chaos. (The full walkthrough: C Drive Full? What’s Eating Your Storage.)

Step 2: Ask Windows Whether Cleanup Is Even Recommended

If you specifically want to check WinSxS, right-click Start, open Terminal (Admin), and run:

DISM /Online /Cleanup-Image /AnalyzeComponentStore

This doesn’t delete anything. It analyzes the component store and reports its actual size and whether Component Store Cleanup is Recommended. Instead of guessing from File Explorer, you’re asking Windows servicing, “Is there actually cleanup available here?” That’s a much better question than “Can I delete the scary folder?”

Step 3: Run the Supported Cleanup

If the answer is Yes, run:

DISM /Online /Cleanup-Image /StartComponentCleanup

That tells Windows to remove old, superseded components it no longer needs. Let it finish — it may look frozen, because command-line tools are apparently required to make you question your life choices. Then restart and check your storage again. You may get back less than you hoped. That’s normal.

What About /ResetBase?

You’ll see a more aggressive version recommended online:

DISM /Online /Cleanup-Image /StartComponentCleanup /ResetBase

I don’t recommend it for a home PC just because the drive is full. ResetBase removes your ability to uninstall the updates that are currently installed — they become the new permanent baseline. If one of those updates causes a problem later, you can’t roll it back. Congratulations: you’ve turned a storage cleanup into a commitment ceremony.

Leave ResetBase alone unless you understand that tradeoff and actually need the space.

What If Your Drive Is Still Full?

If WinSxS still looks big afterward, that doesn’t mean something’s wrong. It’s supposed to exist, and it’s supposed to take up space. Modern Windows isn’t small — shocking, I know. The operating system with three different places to change settings and a weather widget nobody asked for is not tiny.

If your C: drive is still full after cleanup, the answer may be boring: uninstall apps, move personal files, clean up videos and downloads, or upgrade to a larger drive. There’s only so much you can do with a tiny C: drive before Windows turns it into a storage hostage situation.

But the answer is still never “delete the biggest scary folder in C:\Windows.” (A few others belong on that list too: Don’t Delete These Folders From Your C Drive.)

The Short Version

1. WinSxS is the Windows component store — it’s how Windows updates, repairs, and services itself.
2. File Explorer makes it look bigger than the space you can actually recover.
3. Never manually delete it, move it, take ownership of it, or let a “cleaner” app shrink it.
4. Clear temporary files and your own large files first.
5. Run DISM /AnalyzeComponentStore to see whether cleanup is recommended.
6. If it is, run DISM /StartComponentCleanup. Skip /ResetBase unless you understand the tradeoff.

That’s the safe path. Not the exciting path — the safe path. And with Windows, boring is usually better than reinstalling.

And remember my friends… stay grumpy.