Download speed slows down when desktop pc is turned on.

[RagingRabbits]

I have 10mbps download and upload speeds but when i turn on my pc all my other devices become very slow and internet speed test shows 0.12 mbps download speed or something very low but my upload speed still stay at 10mbps .
What is the problem with my pc ?

 

[TJ Hooker]

You can use resource monitor on your PC to see what process(es) are using your network bandwidth.

 

[The Paladin]

I would change the network cable associated with that pc, if no change I would switch network card in the pc itself

 

[Solandri]

Hopefully it's a hardware problem. As stated above, a bad network cable can cause interference with the switch/router, leading to problems relaying packets from other computers. (On some switches you can create a similar problem by plugging a network cable into two ports.) Sometimes the network card/port itself is bad. If the computer has a second ethernet card or a WiFi module, try using that to connect instead.

The fact that your upload speed is unaffected is not encouraging though. That suggests it's not a hardware problem. I've encountered this problem with several businesses on slow Internet connections. Most of the time the culprit has been Windows 10 Update. It was in the process of downloading a huge (for the bandwidth) update which was crowding out almost all other network traffic. Another time it was the Adobe Acrobat update service (that thing is persistent and resists almost all attempts to stop it from auto-running). You can test it by temporarily disabling the Windows Update service and see if the network usage drops. Also check out other programs which might want to auto-update (like Adobe Acrobat, anti-virus, etc).

The problem was exacerbated by the staff keeping the computer turned off except only when they needed it because "it slowed down the Internet". That allowed the number of pending updates to build up, increasing the number of MB which needed to be downloaded, thus ensuring the problem would continue for longer.

Leaving the computer on over a weekend or two when the network wasn't in use (M-F businesses) usually solved it (gave it enough time to complete downloading the updates). After that, I left instructions to keep the computer turned on overnight. It sucks to be wasting electricity like that, but when Microsoft removed the Windows Update configuration options in Win 10, they didn't leave you any other choice. In the case of a home computer, you could try taking it to the house of a friend who has much faster Internet, and let it complete the update there.

 

[The Paladin]

you could do a ping test and see how many packets lost you got run ping from pc to router or to google for example, 8.8.8.8 (dns server from google) and see the % of lost packets... use the command ping 8.8.8.8 -t ( use ctl-c to stop it) let it run for a minute and see result. (test before and after changing cable.)
also make sure your cable modem is running properly (I suggest doing a power reset on it for 30 seconds to make sure)

 

[RagingRabbits]

Thanks for all your replies ! I changed my router and seemed to have solved the problem Thanks everyone !!