Delete the Windows.old Folder Safely (Free Gigabytes)

The fastest way to delete the Windows.old folder is Settings > System > Storage > Temporary files, tick "Previous Windows installation(s)," and hit Remove files — that alone recovers the space on Windows 11 and Windows 10 in under two minutes, no Disk Cleanup, no permissions battle. The only time you need anything more is when Windows throws an Access Denied error while deleting it manually, and there is a fix for that too, further down this page.

Here's the part almost nobody mentions: Windows.old is not a leftover mistake. It is your safety net after an upgrade, and Microsoft wants it to disappear on its own after a set window — it is supposed to clean itself up. When it does not, and you are staring at 15, 20, sometimes 40 GB locked up on a drive that is already tight, that is usually a sign the automatic cleanup got interrupted, not that something is broken.

Jake's laptop had 6 GB of free space left on a 128 GB SSD, and a customer was standing at the counter waiting for him to email an invoice. The email client wouldn't even open. He'd upgraded to Windows 11 three weeks earlier and never went back to check what the upgrade left behind.

It's a common story, and it's an easy fix once you know where to look. The rest of this guide covers the fastest route for both Windows 11 and Windows 10, plus what to do when the fast route refuses to cooperate.

What Windows.old actually is (and why deleting it is safe)

Windows.old shows up on your C: drive any time you do an in-place upgrade rather than a clean install — Windows 10 to Windows 11, one Windows 11 feature update to the next, or a repair install over an existing system. Inside it, Windows keeps a copy of your previous installation: the old Windows folder, your old Program Files, and a Users folder with your old profile data. It exists for exactly one reason — so that Settings > System > Recovery > "Go back" can restore your previous version if the new one causes problems.

Win + R, by the way, is the Run box — a small "type a command and press Enter" window that's faster than clicking through menus once you know the command. You'll see it referenced a few times below, and every path we give also has a Settings-menu equivalent if you'd rather click.

Why it's safe to delete, once you're past the rollback window

Once you've confirmed the new version is working — your programs open, your files are where you left them, hardware is behaving — you no longer need the "Go back" option, and Windows.old is just dead weight. Deleting it does not touch your current installation, your current Program Files, or any file you've created or edited since the upgrade. It only removes the old copy.

Worth saying plainly, since a fair amount of advice online gets this backwards: Windows.old is not where your documents, photos, or downloads "went" after the upgrade. The upgrade process migrates your actual working files forward into the new installation; Windows.old is a separate, complete snapshot of the old system left behind purely for the rollback option. If a file genuinely seems missing after an upgrade, it's far more likely to be a settings or default-folder-location issue than something trapped inside Windows.old waiting to be rescued.

Windows 11: delete it through Settings (the fastest route)

Windows 11 moved most of this into Settings, and it's genuinely the quickest path now — faster than the old Disk Cleanup app most guides (including our original version of this one) still lead with.

Step by step

1. Open Settings — Win + I opens it directly.
2. Go to System > Storage.
3. Under "Storage management," click Temporary files.
4. Look for "Previous Windows installation(s)" in the list — this is Windows.old. Its size is shown right next to it, so you'll know exactly how much you're about to recover before you commit to anything.
5. Check that box (and Delivery Optimization Files or Windows Update Cleanup if you want the extra few hundred MB — those are unrelated but sit in the same list).
6. Click Remove files, and confirm.

This scans and deletes in place; you don't need to reboot afterward, and there's no separate confirmation dialog about "reverting" — Windows already knows you're past that option once you've told it to remove the files here.

Let Storage Sense do it automatically from now on

If you'd rather never think about this again, turn on Storage Sense. Settings > System > Storage > Storage Sense (it's a toggle near the top of the Storage page, separate from the manual Temporary files link above). Turn it on, then open "Configure cleanup schedules" underneath it, and you'll find a setting called "Delete previous versions of Windows" with options like "10 days after upgrade," "20 days," "30 days," or "Never."

Set it to 10 days and you'll never accumulate a stale Windows.old again — it clears itself out automatically once you're safely past the point where you'd realistically want to roll back.

Windows 10: the Disk Cleanup route

Windows 10 doesn't have the same "Previous Windows installation(s)" line inside the Storage > Temporary files screen the way Windows 11 does, so Disk Cleanup's system files mode is still the reliable path here.

1. Type Disk Cleanup into the search box and open it, or run cleanmgr from the Run box.
2. Pick your C: drive if it asks which drive to clean.
3. Click Clean up system files — this is the button that matters; the plain Disk Cleanup window that opens first doesn't include Windows.old at all.
4. Wait for it to rescan (it needs to, even if you just ran it a minute ago).
5. Scroll down to Previous Windows installation(s) and check it, along with anything else you want gone.
6. Click OK, then Delete Files to confirm.

One honest note if you're still on Windows 10: support for Windows 10 ended October 14, 2025. It still runs, still boots, and Disk Cleanup still works exactly as described above — but it no longer gets free security updates unless you're enrolled in Extended Security Updates. If freeing up this space is part of getting a machine ready to keep using a while longer, it's worth checking whether it's eligible for Windows 11 first (Settings > Windows Update will tell you), and if not, whether ESU enrollment makes sense for it.

"Access Denied" when deleting Windows.old — the ownership fix

This is the fix our original post covered, and it still works today, on both Windows 11 and Windows 10. You'll need it if Settings or Disk Cleanup won't remove the folder, or you're trying to delete it manually and Windows blocks you because a system account, not your user account, owns the files inside it.

Take ownership of the folder

1. Right-click Windows.old. On Windows 11 the option you want, Properties, is at the bottom of the short menu — you don't need "Show more options" for this one.
2. Open the Security tab, then click Advanced.
3. Next to Owner, click Change.
4. In the box under "Enter the object name to select," type your Windows username (or type Users to hand it to the whole Users group), then click Check Names and OK.
5. Back on the Advanced Security Settings window, check Replace owner on subcontainers and objects.
6. Click OK, and confirm if Windows asks whether you want to proceed — you do.
7. Give it time. On a folder this size, ownership changes across every file and subfolder can genuinely take several minutes; the window will close on its own when it's done.

Once that finishes, right-click Windows.old again, choose Delete (or select it and press Shift+Delete to skip the Recycle Bin, which is worth doing given the size), and confirm.

The command-line route, for anyone who'd rather script it

Disk Cleanup has a command-line mode that's handy if you're setting up several machines — a small shop like Jake's, doing this on every trade-in laptop before resale, is exactly the case where it earns its keep.

1. Open the Run box and type cleanmgr /sageset:65 and press Enter. The number after the colon is just a slot to save your settings under — 65 is a safe, commonly used choice that won't collide with anything else on the machine.
2. Check the boxes you want, including Previous Windows installation(s), then click OK. Nothing is deleted yet — this step only saves your selections.
3. From then on, run cleanmgr /sagerun:65 any time (or drop it into a scheduled task or a script) and it cleans up exactly what you selected, no dialog boxes, no clicking through.

This isn't faster the first time — it's faster the tenth time, which is the whole point if you're repeating this across machines.

Not ready to delete it yet? Free up space another way first

If you'd rather sit inside the rollback window a little longer — a work machine where you genuinely want a few more days to be sure everything's fine before committing — you can still recover meaningful space without touching Windows.old at all. The same Storage > Temporary files screen (or Disk Cleanup on Windows 10) lists other categories separately: Delivery Optimization Files, Windows Update Cleanup, Recycle Bin contents, and Temporary internet files typically account for a few gigabytes on their own, and clearing those has zero effect on your ability to roll back. It buys you breathing room while you decide, rather than forcing the Windows.old decision before you're ready.

Windows 11 vs Windows 10: where people get stuck

These steps are the same on both versions once you're inside Disk Cleanup or the Advanced Security window — the differences are all in how you get there.

Right-click menu is shorter on Windows 11

Windows 11's right-click menu shows fewer options by default. For deleting Windows.old you generally won't need to dig further — Delete and Properties are both visible on the short menu. But if you're following an older guide (including an earlier version of this one) that references an option you can't find, click Show more options at the bottom of the menu, or hold Shift and right-click, to bring back the full classic menu.

File Explorer's default view moved

If you're browsing to C:\ manually instead of going through Settings, note that File Explorer now opens to "Home" by default rather than "This PC." You can still get to your drives — there's a "This PC" shortcut in the left-hand pane — but the landing page itself changed, and it trips people up mid-guide when the folder they expect to see first isn't there.

Which method should you actually use?

All four methods above end up in the same place. Here's how they actually differ, side by side, so you're not guessing which one to reach for.

Automating it across a fleet of machines

If you're responsible for more than a handful of PCs — a small office, a classroom, a shop like Jake's that images several trade-in laptops a month — doing this by hand on every machine wastes real time. Once you've saved your selections with cleanmgr /sageset:65 as covered above, you can wire cleanmgr /sagerun:65 into Task Scheduler as a scheduled task — weekly, or triggered on startup — and it quietly clears Windows.old and everything else you selected without anyone needing to click through Settings on each machine. For a one-off batch instead of a recurring schedule, the same command dropped into a simple batch file or PowerShell script and run against each machine gets you there just as well.

Storage Sense's "Configure cleanup schedules" setting can also be pushed out via Group Policy on Pro, Enterprise, or Education editions if you're managing machines centrally rather than touching each one — useful if you'd rather set the 10-day rule once, centrally, than rely on it being turned on locally everywhere.

The cases that don't fit the standard steps

"Previous Windows installation(s)" isn't in the list at all

If you don't see that line in Storage > Temporary files or in Disk Cleanup's system files scan, the most likely explanation is that there's genuinely no Windows.old on this PC — it was already deleted, either by Storage Sense automatically or by you at some point, and something else is eating your disk space. Sort the Temporary files or the "See what's taking up space" list by size and check what's actually large before assuming this guide applies.

You've upgraded more than once and there's more than one leftover folder

Windows only keeps one Windows.old at a time — a new upgrade normally replaces or clears the previous one rather than stacking a second copy. If you're seeing more space taken than a single Windows.old would explain, check Storage's full breakdown for Windows Update Cleanup and old driver packages too; those accumulate separately and get bundled into the same "clean up" conversation, but they're not Windows.old itself.

Laptops and low-storage devices where the upgrade almost didn't fit

On a laptop with a small SSD, Windows.old showing up right after an upgrade can leave you with almost no working space until you clear it — sometimes low enough that Windows itself warns you before you've even opened Settings. On these machines, the Settings > Storage route (Windows 11) or Disk Cleanup (Windows 10) is worth running the same day as the upgrade rather than waiting out the automatic window, precisely because there's so little headroom to begin with.

Remote desktop and VM setups

All of this works identically over Remote Desktop or inside a virtual machine — there's nothing about Windows.old or its cleanup tools that requires local, physical access. The one thing to check first on a VM is that the virtual disk itself has room to spare during the ownership-change step; on a nearly-full virtual disk, that process can stall in ways that look like a permissions failure but are actually a disk-space failure.

Antivirus or endpoint software interrupting the ownership change

On machines running third-party antivirus or business endpoint protection software, the ownership-change step above can run noticeably slower, or occasionally appear to hang, because the security software is scanning every file as ownership shifts across it. This isn't a sign anything's broken — give it time before assuming it's stuck. If it genuinely never completes after a long wait, temporarily pausing real-time protection for the few minutes the change takes (then turning it straight back on afterward) usually clears it.

Windows already rolled itself back — is Windows.old still there?

If Windows automatically reverted after a failed update (this can happen on its own within the first few days if the update process detects a serious problem), it typically cleans up after itself as part of that rollback, and you may find little or nothing left to delete. Check Storage > Temporary files first before running through the full ownership fix — there's a decent chance the work is already done.

Dual-boot setups

On a machine set up to dual-boot Windows with another OS, Windows.old behaves the same as on a single-OS install — it only concerns the Windows partition and your previous Windows installation on it. It has no effect on, and isn't affected by, whatever else is installed alongside it. Delete it the same way you would on any other machine.

Do you need a third-party cleanup tool?

Honestly, no — not for this specific job. Tools like WizTree or TreeSize are genuinely useful for visualizing where your disk space is going in general, folder by folder, and they're worth having if you're chasing down space eaten by something less obvious than Windows.old. But for Windows.old itself, they don't do anything Settings, Disk Cleanup, or the ownership fix above can't already do, and running a third-party tool with elevated permissions against system files is one more thing that can go wrong for zero extra benefit here.

One thing to check before you delete it

Windows.old contains a full copy of your old user profile — documents, browser data, saved logins in some cases, whatever was on your old desktop. If you're clearing it off a machine you're about to hand to someone else, resell, or return, that's the moment to actually look inside Windows.old\Users\ once before you delete it, rather than assuming the upgrade already carried everything forward. It's a five-minute check that avoids a much worse conversation later if something important never made the jump.

It's also worth treating this as the natural prompt to check whether you have a real backup at all, separate from Windows.old. Windows.old was never meant to function as a backup — it's a rollback mechanism with an expiration date, not somewhere you should be relying on to keep anything long-term. If a machine has never had its important files backed up anywhere outside itself, an upgrade like this is as good a moment as any to fix that, whether that means an external drive or a cloud backup service, before the next upgrade or a failing drive makes the decision for you.

Jake ran the Settings route while the customer waited — two minutes, 19 GB back, invoice sent. He didn't need the ownership fix at all, which is the outcome most people get now that didn't exist when this guide was first written.

Frequently asked questions

Is it safe to delete Windows.old?

Yes, once you're confident the current install is working properly. The only thing you lose is the "Go back to the previous version" recovery option — nothing about your current files, apps, or settings is affected.

How much space does Windows.old usually take up?

It varies a lot depending on how much was installed before the upgrade, but it commonly runs from around 10 GB to 30 GB or more. Settings > Storage > Temporary files will show you the exact figure for your machine before you delete anything.

Why does Windows.old disappear on its own sometimes?

If Storage Sense is turned on with a "delete previous versions of Windows" schedule set, it clears Windows.old automatically once that window passes. That's expected behavior, not a bug.

Can I just delete the folder normally, like any other folder?

You can try, but Windows commonly blocks it because some files inside are owned by the SYSTEM account rather than your user account. That's what triggers the Access Denied error and why the ownership fix or a built-in cleanup tool works more reliably than a plain Delete.

Will deleting Windows.old speed up my PC?

It frees up disk space, which matters a lot if you were nearly full, but it won't make a healthy PC with plenty of free space run noticeably faster. Don't expect a performance boost if space wasn't the bottleneck to begin with.

I deleted it and now I regret it — can I get my old Windows version back?

No. Once Windows.old is gone, the "Go back" option goes with it, and there's no built-in way to reconstruct it. Your only path back to an older Windows version at that point is a fresh install, which means starting over rather than reverting.

Does this work the same way after a Windows 11 feature update, not just the Windows 10-to-11 upgrade?

Yes. Any in-place upgrade — feature update to feature update, or the original Windows 10-to-11 jump — creates the same kind of Windows.old folder, and every method on this page applies to it the same way.

What's the difference between Windows.old and the WinSxS folder?

They're unrelated, even though people mix them up because both can be large. Windows.old is a full copy of your previous installation, safe to delete once you're past the rollback window. WinSxS is part of your current, active Windows installation — it stores component versions Windows itself depends on — and you should never delete it manually; use the built-in "Windows Update Cleanup" option in Disk Cleanup or DISM if you want to trim it.

Do I need administrator rights to delete Windows.old?

Yes. Both the Settings route and the ownership/Disk Cleanup routes require an administrator account. If you're on a standard account, you'll be prompted for admin credentials at some point in the process.

How long does Windows keep Windows.old before deleting it automatically?

That depends entirely on your Storage Sense schedule if you have one enabled — there's a specific setting for it under Configure cleanup schedules, with options ranging from 10 days up to never. Without Storage Sense turned on, it will simply sit there indefinitely until you clear it manually.

My PC says it can't upgrade because there isn't enough disk space, but I have plenty free. Could an old Windows.old be the cause?

It's worth checking before you assume the space estimate is wrong. A stale Windows.old sitting from a previous upgrade eats into the free space the installer needs for the new one, so clearing it first is a reasonable troubleshooting step if you're getting a low-space warning on an otherwise roomy drive.

Is there a risk to using the /sagerun command-line method instead of the graphical Disk Cleanup?

No added risk — /sagerun runs the exact same cleanup routine as the graphical version, using whatever selections you saved with /sageset. It just skips the dialog boxes, which is why it's useful for repeating the same cleanup across multiple machines.

Can I move Windows.old to another drive instead of deleting it, to keep it as a backup?

Not reliably, and it isn't worth trying. Windows.old is built to work from its exact location on the boot drive, tied to the current installation's recovery mechanism, and moving it breaks that link without turning it into a usable backup of anything. If you want a genuine safety copy of your old files before clearing this out, copy the specific documents or folders you care about to an external drive or cloud storage instead — that's an actual backup; a relocated Windows.old is not.

Should I check what's inside Windows.old before deleting it?

It's not necessary on your own everyday PC, since your current profile already has everything you're actively using. It becomes worth doing specifically when you're preparing a machine to hand off to someone else — a resale, a return, or a family member's old laptop — where you want to be sure nothing important from before the upgrade got left behind.

Does a full disk from Windows.old ever stop an update from completing?

It can contribute to it. Updates and upgrades need a chunk of free space to stage themselves before they install, and a stale Windows.old already eating tens of gigabytes narrows that margin considerably. If an update keeps failing partway through on a drive that's otherwise nearly full, clearing Windows.old first is a reasonable thing to try before digging into anything more complicated.

Revision note. Originally published August 2016, when the ownership-and-permissions workaround covered on this page was genuinely the only reliable way to clear this folder. Rewritten for Windows 11 and Windows 10: Microsoft has since added a direct route through Settings > Storage, plus Storage Sense automation that clears Windows.old on its own schedule, so most people won't need the manual fix at all anymore — it's kept here as the fallback it's become, for the cases where the easy route doesn't cooperate. If you've been fighting a full drive to get here, hope the two minutes this takes gives you some real breathing room back.