I'm fairly frustrated by this problem and would greatly appreciate your help.
Alright, so here's the situation:
My computer (computer 1) is connected by LAN (cat5) to another computer (computer 2). Computer 2 is connected to a wireless router by a wireless card. Computer 1 does not have a wireless card. Both computers are running Windows 7.
This worked wonderfully until sometime this afternoon. Without me changing anything related to the network, my internet connection slowed to about 2-4 kbps and hasn't recovered since then. All 4 of the other computers in the house connect at the same speed as usual, so the problem is only related to my computer.
What I've tried:
Rebooting the router.
Windows 7's troubleshooter for network problems.
From an elevated command line:
Did a system restore to a day ago (when it worked perfectly)
Set my BIOS to optimized defaults.
One more thing: I just plugged my ethernet cord directly into the router/modem and internet works! In my mind, this narrows the problem down quite a lot.
I've tried connecting this computer (Computer 1) to 3 other computers to receive internet. All three of those receive their internet wirelessly. Therefore, there's a problem with the settings on this computer, but the hardware is fine.
Internet --> Wireless Router ))) Computer 2 --> LAN switch --> Computer 1
--> represents wired connection and ))) represents wireless connection.
My original working configuration that no longer works:
Internet --> Wireless Router ))) Computer 2 --> Computer 1
Why on earth did it stop working? I wasn't changing anything at the time that I can remember, certainly nothing network-related. Anyway, it's working now, so I'm not too worried about, but I'd still like to know what happened.
It sounds like your computer was piggybacked onto another computer. The other computer will take priority over your computer with using the internet.
Other factors come into play as well. The wireless card can only handle so much. From maintaining its connection with the wireless router and then trying to communicate with your computer. The weak link is the wireless card in the first computer.
When you connected the switch you took the load off the wireless card in computer1. Now the wireless is back to maintaining computer 1's signal and your computer is transmitting and working over the wired connection.
If possible, you would ideally want to run a cable from your wireless router to your computer or to that switch. This could possibly bump your connection speed up higher by bypassing computer1 completely and giving your computer direct access to the router and internet access.