One is located in "Microsoft\Windows\SettingSync", called BackgroundUploadTask.
The 2nd is located in "Microsoft\Windows\Device Setup", called Metadata Refresh.
The 3rd is located in "Microsoft\Windows\DeviceDirectoryClient", called IntegrityCheck.
These tasks are enabled by default (status Ready), and cannot be disabled by any regular means. Microsoft made sure of that.
The BackgroundUploadTask task is present in all recent Windows OSs - starting from Windows 7 up to the newly announced Windows 10.
The Metadata Refresh and IntegrityCheck tasks are present in Windows 10.
So, how to disable them:
I have discovered that a single bit in the registry is responsible for enabling/disabling these tasks.
All tasks are located in this registry path:
Since the key is different for each machine, first search for "BackgroundUploadTask".
Right-click on the key > Permissions > Advanced > Disable inheritance > Remove all inherited permissions from this object > click "Add" > click on "Select a principal" > type "Administrators" > CHECK Full Control > OK > CHECK "Replace all child object permission entries..." > OK > OK > OK.
In this key, there is a binary value named "Triggers", which contains a series of bits.
Open it and make sure the format is set to "byte".
Go to the 6th row, 3rd column, and change it from "C0" to "00". Press OK and you're done.
Now, if you open the Task Scheduler, you'll see that the BackgroundUploadTask is disabled.
Do the same for the Metadata Refresh and IntegrityCheck tasks.