On a small business (2008R2 Domain) with about 20 PC's recently upgraded a few to windows 10 Pro and shortly thereafter our puny 1.5 Mb download was maxed out.
I did some reading and ensured that all machines are set to only share updates over the LAN, NOT over the internet.
Next change was via Group Policy to notify of updates but NOT to download them automatically.
Despite these changes these few windows 10 boxes are taking turns hogging all the bandwidth they can get and hurting our operations. The task managers show the 'Service Host: Local System' application is doing it but does not breakdown which service/process is the problem.
EDIT: on at least one machine the 'Download Optimization Service' was found to be the bandwidth hog. Killing it halted the activity so that's at least a clue.
