To clear the Windows Update cache, stop the Windows Update and BITS services, empty the contents of C:\Windows\SoftwareDistribution\Download, then restart both services. This safely deletes stuck or partially downloaded update files so Windows Update can fetch them cleanly, and it often frees several gigabytes. This guide is for anyone whose updates fail, loop, or hang at a fixed percentage.

TL;DR

  • The SoftwareDistribution\Download folder is where Windows stores update files before installing them.
  • Failed updates leave gigabytes of locked, corrupted files stuck there.
  • You must stop wuauserv (Windows Update) and bits (download service) before deleting, or the files stay locked.
  • Deleting these files is safe — Windows redownloads anything it still needs.
  • If updates still fail, run sfc /scannow and confirm you have 15–20 GB free for feature updates.

What is the SoftwareDistribution folder?

The SoftwareDistribution folder, located at C:\Windows\SoftwareDistribution, is the working directory Windows Update uses to download and stage update packages before installation. Its Download subfolder holds the actual update payloads. When an update completes normally, Windows cleans most of this up on its own. When an update fails, stalls, or loops, those payloads stay behind — sometimes several gigabytes — and the corrupted files can block every future update attempt. Clearing the folder forces a clean redownload.

Why can't I just delete the files?

You cannot delete inside SoftwareDistribution\Download while Windows Update is running because the service holds the files open and locked. Two services are involved: wuauserv is the Windows Update service itself, and bits (Background Intelligent Transfer Service) is what actually downloads update payloads in the background. Both must be stopped first, or Windows will refuse the delete with a "file in use" error.

How to stop the Windows Update services

Stop both services from an elevated Command Prompt:

  1. Press Start, type cmd.
  2. Right-click Command Prompt and choose Run as administrator.
  3. In the window, run net stop wuauserv.
  4. Then run net stop bits.
  5. Wait for both "stopped successfully" messages, and leave the window open — you will need it again.

If a service refuses to stop, wait 30 seconds and retry; Windows Update sometimes needs a moment to release a download.

How to empty SoftwareDistribution\\Download

With both services stopped, the files are unlocked and safe to remove:

  1. Open File Explorer.
  2. Navigate to C:\Windows\SoftwareDistribution\Download.
  3. Press Ctrl + A to select everything inside the folder.
  4. Press Delete, and click Continue if prompted for administrator permission.
  5. Confirm the folder is now empty.
  6. Return to the admin Command Prompt and run net start wuauserv, then net start bits.
  7. Close the Command Prompt.
  8. Open Settings › Windows Update and click Check for updates — Windows redownloads the update cleanly.

Delete only the contents of the Download subfolder. Do not delete the SoftwareDistribution folder itself.

Is it safe to clear the Windows Update cache?

Yes. Emptying SoftwareDistribution\Download only removes temporary, redownloadable update files — it does not touch installed updates, personal files, or system settings, and nothing is permanently lost. The worst case is that your next update check takes a little longer while Windows re-fetches the payloads. Your installed Windows version, apps, and documents are untouched.

If the update still fails after a clean redownload, the cause is usually elsewhere: a corrupted system file (run sfc /scannow from the admin prompt) or insufficient free disk space — a Windows feature update often needs 15–20 GB of headroom to stage and install.

What else fills up your Windows drive?

Update leftovers are rarely the only culprit. Once the cache is clear, the bigger wins usually come from update delivery files, hibernation, and forgotten installers. These guides cover the rest of the picture:

For a structured walkthrough of reclaiming Windows storage step by step, see the phone and PC storage cleanup hub.

FAQ

Will clearing SoftwareDistribution delete my installed updates?

No. Clearing the SoftwareDistribution cache only removes downloaded and staged update files, not updates that are already installed. Windows keeps your applied updates and redownloads anything still pending.

Why won't Windows let me delete the files in the Download folder?

Windows locks the files because the Windows Update (wuauserv) and BITS (bits) services are using them. Stop both services from an admin Command Prompt first, then the files delete normally.

How much space does clearing the Windows Update cache free?

It varies, but a stuck or looping update commonly leaves 1–8 GB of payloads in SoftwareDistribution\Download. Large feature updates can leave even more.

Do I need to restart the services after deleting the files?

Yes. Run net start wuauserv and net start bits after emptying the folder, or Windows Update will not function until the next reboot.

My update still fails after clearing the cache — what now?

Run sfc /scannow from an admin Command Prompt to repair corrupted system files, and make sure you have at least 15–20 GB of free space for a feature update.

Keep your storage clean for good

Clearing stuck update files is a one-time fix, but Windows fills back up over time. If you want the same effortless, privacy-first cleanup on your phone, Cleanor for iPhone finds duplicates, large videos, and clutter locally — nothing leaves your device.