What the Windows Update cache is and why it grows
Every update Windows installs passes through the SoftwareDistribution folder on your system drive. Windows downloads the installation packages there first, verifies them, and only then applies them. Ideally the folder empties itself after each successful install, but in practice files accumulate: interrupted downloads stay half-finished, failed updates leave orphaned packages behind, and some files are kept as repair material.
On a healthy machine the Download subfolder holds a few hundred megabytes. After a large feature update, or on a PC where updates keep failing, it can swell to 10 GB and beyond. None of that is user data — clearing it risks nothing except Windows having to re-download pending updates.
- Full and partial update packages downloaded but not yet installed
- Files Windows keeps to repair or uninstall recently installed patches
- Leftovers from failed or stuck update attempts
- Delivery metadata and checksum files the updater uses for verification
- Old log entries and temporary data the servicing stack rarely trims
How to clear the update cache safely, step by step
The folder is locked while the update services are running, so the safe order is: stop the services, clean, start them again. Open Start, type cmd, right-click Command Prompt and choose Run as administrator. Then run two commands, waiting for each to finish: net stop wuauserv and net stop bits. The first stops the Windows Update service, the second the Background Intelligent Transfer Service that physically downloads the files.
Now open File Explorer and go to C:\Windows\SoftwareDistribution\Download (the quick way is to paste the path into the address bar). Select everything inside with Ctrl+A and delete it. Windows may refuse one or two locked files — that is fine, skip them. Return to the admin prompt and run net start wuauserv and net start bits, or simply reboot: on the next start the services re-create the folder automatically. If the services refuse to stop, reboot into Safe Mode and repeat the procedure.
Keeping the cache small and using cleanup to fix updates
After the first cleanup, the folder stays modest for months. Windows 10 and 11 also offer a gentler built-in route: Disk Cleanup's Windows Update Cleanup option (run cleanmgr, click Clean up system files) removes superseded update components from the component store, which is a different, deeper cache. Storage Sense in Windows 11 can clear update leftovers on a schedule as well.
Clearing SoftwareDistribution is also a classic repair step. When an update is stuck downloading at a fixed percentage or fails with an error code, wiping the cache forces Windows to fetch a fresh copy. Kleaner PRO bundles this into its Update Cleaner module — it stops the services, clears the cache and restarts everything in one click, so the manual routine becomes unnecessary.
Questions and Answers
Is it safe to delete the SoftwareDistribution folder?
Yes — Windows re-creates it from scratch. Just clear only the Download subfolder; deleting the whole SoftwareDistribution folder also wipes your update history list.
How much space does clearing the Windows Update cache free?
Usually between 500 MB and 5 GB. On PCs with repeatedly failed updates, or right after a feature update, it can be 10 GB or more.
Will Windows re-download updates after I clear the cache?
Only updates that were downloaded but not yet installed. Everything already applied stays in place — the cache does not affect installed updates.
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