This is also happening to me, I have fios 10/2 and i will drop to speeds of 700kb/1.5k. I have to end some of the svchost proccesses in the task manager in order to fix it, and even then it takes a few minutes for windows explorer to refresh, re-enable and be good again.
This also occured when I used remote desktop.. and utorrent.... its real quirky.. sometimes i reboot and it happen right away and some times i can surf the web for a while and it will just slow down.
I read up on a streaming throttling issue, anyone heard of this?
any help would be good. I really dont want to have to use XP again...