Is it safe to delete Delivery Optimization files?

Yes, Delivery Optimization files are safe to delete. They're a cache of Windows updates and Microsoft Store apps that your PC has already downloaded, kept so it can share them with other PCs. Microsoft itself suggests clearing them with Disk Cleanup when you need space. Nothing on your PC depends on them.

Quick verdict:

• Safe: clearing Delivery Optimization Files in Disk Cleanup or in Settings → System → Storage → Temporary files.
• Safe: running the official Delete-DeliveryOptimizationCache PowerShell command.
• Not recommended: deleting files by hand inside C:\Windows\ServiceProfiles.
• Expect it back: the cache fills again with the next updates, then shrinks on its own.

What is Delivery Optimization?

Delivery Optimization is the downloader Windows uses for Windows updates, Microsoft Store apps and some other Microsoft products. As well as downloading from Microsoft, it can fetch pieces of the same files from other PCs that already have them, and share what your PC has downloaded in return. That's what the cache is for.

According to Microsoft's Delivery Optimization reference, the default settings for home PCs are:

• Download mode: LAN. Sharing happens only with devices on your own network, unless you change it.
• Max cache age: three days. Each file stays in the cache for up to 259,200 seconds.
• Max cache size: 20% of the free space on the drive. Delivery Optimization keeps checking and clears the cache to stay under that limit.
• Cache drive: the system drive (%SYSTEMDRIVE%, usually C:).

The files live in the profile of the Network Service account that runs the Delivery Optimization service (DoSvc), under C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Microsoft\Windows\DeliveryOptimization. You normally never need to go there.

How much space does it use?

The easiest way to check:

1. Open Settings → System → Storage.
2. Select Temporary files and wait for the sizes to appear.
3. Look at Delivery Optimization Files.

Disk Cleanup shows the same line, with its size, on its first screen.

A disk analyzer such as SquirrelDisk is less useful here. It runs without administrator rights, so it can't read inside the Network Service profile, and that folder will look smaller than it really is or empty. It's also inside C:\Windows, where SquirrelDisk never deletes anything. Use it to find the big folders elsewhere on your drive, and leave this cache to Windows.

How to delete it safely

With Settings

1. Open Settings → System → Storage → Temporary files.
2. Tick Delivery Optimization Files. Untick anything you want to keep, such as Downloads or Recycle Bin.
3. Select Remove files.

With Disk Cleanup

This is the method Microsoft describes for clearing the cache by hand:

1. Press Start, type Disk Cleanup and open it.
2. Tick Delivery Optimization Files.
3. Click OK, then Delete Files.

If the entry isn't there, click Clean up system files first.

With PowerShell

Delivery Optimization has its own cmdlet, used in Microsoft's testing guide. Open Terminal (Admin) and run:

Delete-DeliveryOptimizationCache -Force

-Force skips the confirmation. Microsoft's guide also adds -IncludePinnedFiles, which removes files that were pinned to stay in the cache, usually by an IT department.

Automatically, with Storage Sense

Settings → System → Storage → Storage Sense cleans temporary system files on a schedule when it's turned on. You don't need to do anything special for Delivery Optimization: it already empties its cache after a few days.

What you should not delete

• The folders themselves under C:\Windows\ServiceProfiles. They belong to a system account. Taking ownership to delete them can break the service, and gains nothing over Disk Cleanup.
• Downloads in progress. If Windows Update or the Store is downloading right now, files in the cache may be in use. Clear the cache once the update has finished.
• Policies set by your organisation. On a work PC, cache size and sharing are often managed by IT. Changing them locally may be overwritten, or may go against company policy.

If something goes wrong after clearing the cache, the worst case is that Windows downloads an update again.

How to keep it small

You don't have to do much: the cache already trims itself. If you want more control:

• Turn off sharing with other devices. In Settings → Windows Update → Advanced options → Delivery Optimization, switch off Allow downloads from other devices. Your PC still downloads updates, just not from or to other PCs.
• Limit bandwidth. Under Delivery Optimization → Advanced options you can cap download and upload speeds and set a monthly upload limit. These limits are about your connection, not disk space.
• Limit the cache size (Pro, Enterprise, Education). In the Local Group Policy Editor (gpedit.msc), go to Computer Configuration → Administrative Templates → Windows Components → Delivery Optimization. Max Cache Size (percentage) and Absolute Max Cache Size (in GB) set the limit, and Max Cache Age (in seconds) sets how long files stay. Windows Home doesn't include the Group Policy Editor.
• Move the cache. The Modify Cache Drive policy in the same place can put the cache on another drive, for example D:.
• Check what it's doing. Delivery Optimization → Activity monitor shows how much your PC downloaded from Microsoft and from other PCs, and how much it uploaded, this month.

Better ways to free space

Delivery Optimization Files are just one line in Temporary files. On the same page, Windows Update Cleanup and Previous Windows installation(s) are often larger: see is it safe to delete Windows.old and the SoftwareDistribution folder. For the space that isn't in Windows' own folders, a scan with SquirrelDisk shows which of your folders are biggest, so you can decide what goes.