One computer causes massive increase in ping / ms

Question

For a rather long period of time I have been having an increased ms when playing games etc. This always occurs when my girlfriend starts using her computer, so at the moment I believe that to be the evil that corrupts my otherwise beautiful internet connection.

Keep in mind that we have 5 computers, 4 smartphones + 3 consoles in this house, but the problem only occurs with my girlfriends computer. Everything is fine with everything else turned on. (And this is only when she is browsing. No other background applications are running.

I have tried more or less everything basic that I know:

• Installed new drivers
• Reset the router
• Used ethernet
• Virus scan, nothing found.
• Different browsers, reinstalled with no addons
• Reboot (of course)
• Disk Cleanup / Defrag
• Tried running wifi on different channels & Ghz
• Removed all wireless networks and readded
• Checked DNS settings
• I have also done a reinstall long ago, but the problem still persisted back then.

CMD:

• ipconfig /flushdns
• ipconfig /release
• ipconfig /renew
• netsh winsock reset catalog
• netsh int ipv4 reset reset.log
• netsh int ipv6 reset reset.log

I would appreciate any answers, as this is rather annoying. (I am sorry if I have any grammatical errors, English is not my primary language.)

Answer 1

Just to make sure I understand this correctly: If you do a continuous ping to a certain site, you will get good low ping times under normal circumstances. But if your girlfriend turns on her computer, and it connects to the internet on your network, about 1 minute later those ping times go way up, and then if she turns her computer off, the ping times go back down. Does that sum it up correctly?

If this is true, then her computer must be using a lot of bandwidth somehow. Some common reasons for this are:

1. Her computer is automatically downloading some sort of updates - OS or software updates, etc.
2. Her computer is using online backup and is uploading a backup of her files.
3. Her computer is connected to a file share network and is either downloading files, or is auto-uploading files. If this is the case, hopefully this is something she did on purpose, but some viruses or malware could do this too.

It's possible there is an underlying network issue too with the network and/or the laptop, but I would consider that less likely compared to the things mentioned above.

Answer 2

Is her computer wireless or wired? Try another network card and/or replace the network cable.