Why my internet suddenly lose 90% of it's speed when PC is turned on

Copenhagen_1

Commendable
Sep 23, 2016
7
0
1,510
So guys. i just reformatted my PC and i encountered this problem.
After i reformatted my Internet connection suddenly slowed down by 90%
"Then the windows much be updating" No i don't think so.
i tried a test and i found out that the moment my counter is connect to the modem using router my net will slow down.
I tried speedtesting while my PC is off. my speed is at full speed. i turned on my computer mid way of test and my internet speed suddenly stay at 0.20 mbps. now there should be no update at that time since it's only booting up. really odd problem. this is not the first time i encountered this. whenever i reformat my counter it does this. can someone help me?