Windows 10 System downloading massive amounts of data

due to technical reasons I get my internet via LTE with a data limit of 200GB per month. Yesterday I reached that limit, although I wasn't aware of any major downloads I did. I have only had it for two weeks now, and before my computer (the only one in the network) wasn't connected to the internet for 2 months.

So I looked into the data usage details of Windows, which shows the data usage per programm for the last 30 days, and to my horror saw that the System alone had downloaded over 100GB of data.

Data usage picture 1

I looked into the windows updates history, but they only get to about 25GB in total for the last month. I googled the problem and found a few tips on how to reduce the data loaded by background stuff and pre-installed apps, etc. I set a limit (which of course was already exceeded) to prevent further massive downloads, and set the option to restrict what Store-apps and Windows-features can do in the background. Then I deinstalled a bunch of programs so nothing I don't need loads updates without me wanting that. I also deaktivated that Windows may seed updates from my computer (although that should only affect the upload, and only in my local network where my PC is the only device). At last I reset the statistic to see if it changed anything. Then I booked some more data from my provider so I can keep working.

Now this morning I looked into it, and there are already 4GB downloaded by the System again.

Data usage picture 2

Now I know that there are a lot of features, apps and programs hiding behind System. Is there a way of telling what exactly is downloading so much data? Do you guys have any more advice on what to do? I have no other choice than the LTE option to get internet in my flat.

Thank you all in advance!

PS: If anyone knows of any better suited tags, please add them.

Answer

Here is a list of procedures to reduce background data usage.

• Set the network connection to "Metered" as described by user
  m720.




• Disable contributing bandwidth to nearby computers:
  In Settings > Update & Security > Delivery Optimization, turn off
  "Allow downloads from other PCs".
  Click "Advanced options" and verify that they are all turned off.




• Turn off background apps.
  In Settings > Privacy > Background apps, toggle off apps that use
  background data that you don’t need.




• Disable OneDrive.
  If you are not using OneDrive, disable it by right-click on the Taskbar,
  start Task Manager, select the Startup tab where you can disable OneDrive.




• Disable PC Syncing.
  If you’re using a Microsoft account to log in to Windows, you can do that in
  Settings > Accounts > Sync your settings, and set Sync settings to Off.




• Turn off Live Tiles.
  Except for select apps, you turn that off by right-click on the Tile and setting
  "Turn off live tile".




• Defer Windows Updates.
  This option changes with every release, so consult
  Settings > Update & Security > Windows Update.




• Opt out of Customer Experience Improvement Program.
  Run the Local Group Policy Editor (gpedit.msc), and position to
  Computer Configuration > Administrative Templates > System > Internet Communication Management > Internet Communication settings.
  Double-click "Turn off Windows Customer Experience Improvement Program",
  click "Enabled" and OK.

Note that when Windows Updates or new versions are installed, these settings
might be reset. So periodically you might need to check these again.