You found a folder or a setting called Delivery Optimization while hunting for disk space, and it is not obvious what it is or whether you can get rid of it.
It is Windows getting its updates partly from other computers instead of only from Microsoft, and keeping what it downloads in a cache. On this machine that cache is nearly 700 MB.
I measured it before writing, and my first reading came back as zero across the board, which was wrong.
What it actually does
Microsoft's own description, and it surprises people.
⭐ Microsoft states it on its Delivery Optimization privacy page: it lets you get updates and Store apps "from sources in addition to Microsoft, like other PCs on your local network".
⚡ And it runs both ways. Microsoft: it "also sends updates and apps from your PC to other PCs on your local network".
⚠️ So your machine is a source as well as a destination. That is the part nobody reads twice.
⛔ It is on by default and it has been for years. Nothing was switched on behind your back recently.
The cache, and how long it keeps things
Short, and Microsoft is vaguer here than you would like.
⚡ Microsoft's wording: "Delivery Optimization creates a local cache, and stores files that it has downloaded in that cache for a short period of time."
⭐ A short period is as specific as it gets. ⚠️ We could not find a number anywhere on that page.
⚠️ It clears itself when files age out or the folder gets too big. You are not meant to manage it.
⛔ Which is why deleting it by hand buys you nothing lasting. It refills on the next update.
What this machine is actually holding
Measured, and this is the number people come looking for.
⭐ The cache is 728,036,603 bytes, which is 694.3 MB. Thirteen files, all downloaded.
⚡ The drive it sits on is 453.6 GB with 81.7 GB free. So the cache is under two percent of what is left.
⚠️ If you are short of space, this is not where your problem is. The big items are somewhere else entirely.
⛔ 694 MB is worth knowing. It is not worth an evening. Read it, then go and look elsewhere.
The correction, because my first reading was zero
Printed rather than quietly fixed, because a zero is the easiest wrong answer for you to believe.
⚡ My first attempt asked for two fields that do not exist. Both came back empty. Both printed as 0 MB.
⭐ A missing field and a genuine zero look identical. That is the trap, and it has caught this site before.
⚠️ Asked properly, the same command gives thirteen files and 694.3 MB. Nothing had changed on the machine.
⛔ So check the field names before you believe a zero. Reading a state is only useful when you know what normal looks like.
The upload half, and what this machine has given back
Ours, and your numbers may be as lopsided as these.
⭐ Download mode reads Lan, which means peers on your own network only, not the internet.
⚡ Fourteen peers are known. There are 48 connections to Microsoft's own servers and 45 to cache hosts.
⚠️ Local network connections read zero, and so do bytes uploaded. This machine has taken and given nothing back.
⛔ That is normal on a home connection with one PC. Peer sharing needs another Windows machine downloading the same thing at the same time.
Turning it down or off
Microsoft's route, and there is a middle setting you probably want.
⚡ Microsoft's route: Settings, Windows Update, Advanced options, Delivery Optimization, then the Allow downloads from other devices toggle.
⭐ The middle option is "Devices on my local network". That stops your PC sharing with anything on the internet.
⚠️ Off entirely means every update comes from Microsoft, which is slower on a poor connection and no less secure.
⛔ Microsoft says it checks what it gets: it "gets information securely from Microsoft to check the authenticity of each part" downloaded from other PCs.
What happens on a metered connection?
One sentence, and it is the answer if you are on a data cap.
⭐ Microsoft states it: "If you use a metered or capped internet connection, Delivery Optimization won't automatically download or send parts of updates or apps to other PCs on the Internet."
⚡ So marking your connection metered handles it for you, without touching the feature.
⚠️ That also changes other update behavior, so it is a bigger lever than it looks.
⛔ On a mobile hotspot it matters most. Sharing a cellular connection spends the plan behind it.
Status: measured 29 August 2026. The service, the cache size and the transfer counters all came off this machine, and every quotation is from Microsoft's Delivery Optimization privacy page. ⛔ Nothing was cleared, disabled or changed, no peer or network is identified, and no file name is published.
What is Delivery Optimization in Windows?
Microsoft describes it as letting you get Windows updates and Microsoft Store apps from other PCs on your local network or on the internet, as well as from Microsoft. It also sends parts of updates from your PC to others, based on your settings. It is on by default.
How big does the Delivery Optimization cache get?
Microsoft gives no figure and only says files are kept for a short period. On this machine the cache holds thirteen files and 694.3 MB, on a drive with 81.7 GB free. It clears itself when files age out or the folder grows too large.
Should I delete the Delivery Optimization cache?
There is little point. It refills on the next update and it clears itself anyway. If you genuinely need the space, the cache is under two percent of the free space here, so the real culprits are somewhere else.
How do I stop Windows sharing my updates?
Settings, Windows Update, Advanced options, Delivery Optimization. Turn Allow downloads from other devices off, or set it to devices on your local network only. Marking a connection as metered also stops internet sharing automatically.
The Short Version
- It gets updates partly from other PCs, and sends parts of yours to them.
- Microsoft says the cache keeps files for a short period and gives no number.
- On this machine it holds thirteen files and 694.3 MB.
- The drive has 81.7 GB free, so the cache is under two percent of that.
- Download mode reads Lan here, with fourteen peers known.
- Bytes uploaded and local network connections both read zero.
- Settings, Windows Update, Advanced options, Delivery Optimization turns it down.
- A metered connection stops internet sharing without touching the setting.
Where to Next
Read your own cache size before you decide it is a problem, because it usually is not.
If you want it smaller, set the mode to your local network only rather than off.
Mark a mobile or capped connection as metered and Windows handles the rest.
Leave the folder alone rather than deleting it, since it refills and clears itself.
And if your cache has ever grown past a few gigabytes, tell me the number in the comments. Microsoft publishes no ceiling and somebody should.
Isaac Smith is the founder and editor of PC Glance, a website that covers computers, laptops, and technology. He is a tech enthusiast and a computer geek who loves to share his insights and help his readers make smart choices when buying tech gadgets or laptops. He is always curious and updated about the latest tech trends.