How to Clear Delivery Optimization Files in Windows 11

What Delivery Optimization files are and why they pile up

Delivery Optimization is the technology behind every Windows update download. Instead of one big stream from Microsoft, the system fetches update pieces from Microsoft servers and, if allowed, from other PCs on the internet or your local network. To make that possible it keeps a cache of downloaded pieces on the disk — officially under C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Microsoft\Windows\DeliveryOptimization.

The folder grows with every cumulative update and can balloon after a feature update, when several gigabytes of installation pieces stay cached even though setup is long finished. Storage settings list this as its own category, so you always see exactly how much it holds. Nothing in it is personal data or a user file — it is purely re-downloadable update payload.

• Update pieces fetched from Microsoft or peer PCs — the bulk of the cache
• Files held to resume or repair an update that is still in progress
• Installation leftovers after a feature update, kept until the next cleanup cycle
• Cache location: C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Microsoft\Windows\DeliveryOptimization
• None of it is personal data — every piece can be fetched again from Microsoft

Clearing the files: the two built-in routes

Route one is Settings: System → Storage → Temporary files. Wait until the list is populated with sizes, check “Delivery Optimization Files” and review the other items — the same page mixes in things like Downloads, which you probably do not want to wipe — then click Remove files. Route two is the classic Disk Cleanup: press Win+R, type cleanmgr, run it for C:, click “Clean up system files”, and check “Delivery Optimization Files” there.

Both routes delete the same thing and both are safe on a running system: pieces needed by an in-progress update are simply skipped or locked. Do not bother hunting the cache folder by hand — between the network service's permissions and locked files it is the least convenient way to do what a single checkbox already does. If an update is mid-installation, let it finish first, then clean.

Stopping the cache from growing back

Windows 11 lets you cap the cache instead of watching it grow: Settings → Windows Update → Advanced options → Delivery Optimization → Advanced options. There you can limit the cache size — in gigabytes or as a percentage of the drive — and set how long unused files are kept. The same page shows monthly statistics of downloaded and uploaded data, which tells you how active peer sharing actually is on your machine.

If you never want your PC uploading update pieces to the internet, turn off “Allow downloads from other PCs” on the Delivery Optimization page. The devices-on-my-local-network option keeps sharing inside your own network, which is usually harmless and even useful. Beyond that, this cache belongs to the same family as other update leftovers, and a scheduled cleanup keeps it from accumulating in the first place — Kleaner PRO's scheduler takes Delivery Optimization files out together with temp files and caches, so the multi-gigabyte surprise stops repeating.

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