My Dell laptop running Win 8.1 loads web pages very fast on ethernet cable, but Firefox and Chrome intermittently hang (coming and going every few minutes) and get 'connection was reset' errors while browsing on wifi.
My phone on the same wifi network has no problems.
Nobody else is on the wifi.
I have updated the Intel wifi drivers on the laptop.
It may well not be the computer that is the problem. It could be your ISP, you should be able to log into the modem to check for any issues.
You may also want to try rebooting the modem. Yes I know you said the other device works fine, but different devices react differently. I have had two phones and a laptop on the WiFi here and they have no issues, but the desktop is more sensitive to the changes.
If these don't work/help, try this....
First, make sure your laptop is 'not' connected to the modem/router via an Ethernet cable and follow the steps:
1. Go to "Control Panel".
2. Next go to "Network and Internet" and then "Network and Sharing".
3. Now click on "Manage Wireless Networks".
4. On this screen, remove all wireless connections by "right clicking" on it and select "Remove network" from the drop down menu.
5. After doing this, close the open windows and reboot the computer.
6. Once the computer is fully reloaded, scan for the "Wi-Fi networks".
7. Click on the available network that you want to access and select "connect".
8. It takes a moment, but then you will be asked to give a password for your Wi-Fi connection. Type in the password and click the "connect" button.
It should now be connected.
If that doesn't help, and you said it works via Ethernet, then your WiFi card may be going. You can either look to replace it/have it replaced, or get an external (plugs in via USB) WiFi card.