Why is the internet slow on only one of my computers?

[Gobbling_Monkey]

Hello. I have an HP Envy 17t-j100. I have a TP-Link Archer C9 router. I usually get 18 mbps internet speed on all of my devices. However, I have lately been getting only 7 mbps on only my laptop. It usually alternates between normal and slow every 30 minutes. Here are all the things I have tried.

• 
  Replaced Wireless Card (To be able to connect to 5 GHZ wifi)
  Scanned for viruses (Found 2 viruses, it was better for a day, then became slow again, and I can't see any more viruses)
  Reset router and modem
  Looked for programs that may be slowing my internet down (I don't think there is anything. I may be wrong. I don't have Amd Quickstream)
  Connected to router over ethernet

None of these have helped. Do I probably still have viruses and Malwarebytes can't find them? Am I missing something? I can't figure out why only my laptop has slow internet. I can't watch any video without buffering. Here is a link of all the programs installed on my computer, if it is any help. Thank you.

 

[ilovecs22]

if you found 2 viruses it could be infecting your internet/router i would get your internet provider a call

 

[Gobbling_Monkey]

if you found 2 viruses it could be infecting your internet/router i would get your internet provider a call

Hello and thank you for your reply. So I did not even know routers can get Malware. I did some research on how to check for Malware on a router. I found out the DNS server, Googled it, and got the right secondary DNS server. I am not sure if that's all I need to do. I barely understand this. Does that mean my router is fine? Also, how else should I check? Kaspersky calls the network insecure, if that helps.

 

[ilovecs22]

the dns severs have nothing to do with that it will still be on your router and will probabbly continiue infecting everything thats on your network
calll your internet provider for the sake of your devices