Win7 PC Inexplicably Very Slow Internet

rynen

Reputable
Sep 9, 2015
2
0
4,510
I have tried to solve this on my own and I am completely dumbfounded at what it could be.

Here is the issue:

Desktop computer is incredibly slow over ethernet and wifi connections. It's currently maxing out at 10-15mbps, while all other devices in the home are running at 80+.

Details:

- Lenovo M58 Desktop PC, running Windows 7 64bit, 4GB Ram, C2D processor. Computer runs great, other than over the web.
- Internet package is incredibly fast. I am reaching speeds of 80mbps over my laptop and all other devices I use to test internet speed.
- Internet ran great for about a year until my service provider replaced the modem. It ran for about 3 weeks at top speeds, and then decided it wanted to be slow.

What I've Done so far:

- Fresh install of Windows
- Reinstalled all network drivers
- Tried plugging in a USB wifi adapter, and connecting wirelessly (same slow speed)
- Reset the router to factory settings
- Disabled firewall, antivirus not installed.
- Stopped all processes that aren't necessary to running windows/browser testing speed
- There are NVidia display drivers installed, but there is nothing running as a process, potentially throttling the speed (seen this as an issue in other forum questions)

The Frustration:

- When I run the ethernet from my laptop (on wifi) to the PC's ethernet port - full speeds. I will then put the ethernet cable back into the router, it goes back to 10-15mbps.

I'm thinking there is a communication problem between the router and the PC, but don't have the networking-savvy to figure it out any further.

Thanks for any help you can provide!
 

rynen

Reputable
Sep 9, 2015
2
0
4,510
OK, so after some serious trial and error, I've found that it's due to a Critical Windows Update. I did system restore to the earliest point, and got full speeds.

After windows installed 100+ updates, internet went back to being slow again. Once I system restored again, back to full speeds. I disabled Windows updates and it's now working fine.

It doesn't really get to the root of the problem, but I now have a functioning PC.

Any further ideas on how the Windows Update could throttle speeds?