Kitz Forum

Computers & Hardware => Networking => Topic started by: pooclah on January 04, 2015, 08:46:39 PM

Title: Windows 7 slow downloads (solved)
Post by: pooclah on January 04, 2015, 08:46:39 PM
This is how I fixed my slow download throughput (not internet speed)

Yesterday I decided to run windows update on a neglected PC in our house (it acts as a media centre/backup machine/test machine (for me – runs other OS for me to play with)) and as per my preference it only notifies of updates.  It found 300MB’s worth and I duly researched each one (no I didn’t, too many, too lazy) and hit the download button.  I thought the download would take a couple of minutes on my 72Mbps connection, but 5 minutes later it was still downloading, nowhere near starting to install.

After the updates had finished installing and the PC rebooted I ran a speed test just to see if there was an issue – 3.7Mbps down 16.5Mbps up.  Not right, so I did a speed test on another machine – 66Mbps down 17Mbps up.  Time to start troubleshooting.

I rebooted the PC into Windows 8.1, speed test result was full speed up & down, so not a hardware fault.  Back into Windows 7 and the tests still showed poor download speeds.  After changing drivers, adapter settings and god knows what else without result I gave up. 

Today I took a fresh look and one test was to download a large file.  I noticed that after a couple of minutes the download was getting faster and that the download speed increased the longer the download went on, almost to full speed by the end of the download.  Then it hit me – Windows autotuning, so I did a bit of googling and found this (https://www.duckware.com/blog/how-windows-is-killing-internet-download-speeds/index.html)

Lo & behold the command “netsh interface tcp set heuristics disabled”   solved all my problems, downloads back to full speed.

WARNING
What and how it corrupted my low level network settings I don’t know and I’m not saying this is a cure for slow internet speed, but if you have an issue similar to the one I had it’s worth trying as a last resort.