I don't use defender, as I have already stated so can't help with configuring it.
To be clear; no computer tech worth spit will advise you to remove an anti-virus program unless you intend to replace it with something else like avast or avg.
No I can't configure your system for you because doing that on a forum instead of just looking it up yourself is impractical… My best advise I can give you is what I would do so in this order;
1. Ring your service provider and ask them if your account has been restricted or is there any faults detected on the line… there is little you can do about some git of a farmer cutting the cable with his hole digger but at least you know the issues isn't at your end.
2. Goto
http://www.speedtest6.com/ and record a speed test.
3. Turn off automatic updates for any programs… includes; anti-virus, java and specially windows… stop onedrive from syncing files when ever the mood takes it and make any metro apps (
like the Microsoft store) ask you permission before going online.
4. Reboot and go back to
http://www.speedtest6.com/ and record a new speed test.
5. Disable any torrent download software and remove any 3rd party junk software that claims to be optimising your internet connection… and "yes you guested it" record a new speed test.
6. Go to a mates house (
ideally whom is with a different service provider) or some work site that allows wireless internet ie, hotels, mac Donald's café etc and record a new speed test.
The point is that you build up a reliable picture of network speeds based on actual data instead of guessing.