My dell laptops wifi is not working correctly?

[701]

Ok so i have a Dell inspirion 3521 windows 8.1. I had windows 8 i upgraded it a few days ago. So anyways my wifi was working great for a few days then all the sudden quit. When it quit it would connect to the wifi router bit would not so the SSID/name or network and said limited. I fixed that. Now when i connect, it will say connected to the wifi show the name of wifi network and Internet access. But hen i go to get on google chrome it won't load the website. it brings up a page saying DNS server lookup failed. It also says "Check your DNS settings".Error code: DNS_PROBE_FINISHED _BAD_CONFIG I have turned my firewall and antivirus off. I have tried putting 8.8.8.8 and 8.8.4.4. That doesnt work. I have tried others too. as well as the IP adress. It worked great when i had Windows 8. After i upgraded to Windows 8.1 it worked for a few days then all the sudden quit. Its up to date. What could cause this? I am getting the wifi from my grandparents house next door. I've also tried my neighbors wifi it says "Unknown" and Limited access. as the name and connection. what can i do to fix this. I'm having to use my phone for internet it sucks. any help is appreciated! Here is my system info.

System: Processor: Intel® Pentium® CPU 2117U @ 1.80GHz 1.?80GHz Installed memory (Ram): 4.00 GB (3.87 Usable)
System type: 64-bit Operating sys. x64 based processor. Windows edition: 8.1-- was Windows 8.

[FaScEs]

Things like this are hard to pin point, I would hard wire your computer / laptop and do a windows update.

[Allen J.]

I think the better idea is reinstall the OS, it may happen due to any file missing.