The Windows 10 “Anniversary Update” was just deployed today - since the problem seems to be a Windows one and not an Edge / Chrome one, my guess is it has something to do with that. I’m installing the update; I’ll follow up once I have that downloaded and installed.
There are around 350 million Windows 10 machines, and it’s a fairly reasonable guess to say at least one percent of them are trying to download the update right now. Peer-to-peer updates should help a little, but I’ve been waiting for a few minutes and am still at 0%.