Limited to No Connection - Wireless

Hello,
I live in an apartment with 3 other people. They can all connect to the internet wirelessly without a problem. If I connect with the Ethernet cable I do not have any issues. When I try to connect wirelessly it is inconsistent. Sometimes I can’t connect at all, sometimes I can connect to the router but it will say I have “No Internet access” and other times (like this one) I can connect but it says I have “Limited Connectivity”. I went home last week and could connect to my home’s router and internet without any issues and the connection won’t drop at all. I have to constantly disconnect from my router and reconnect for it to work (which is half the time). And when it finally does work, it won’t stay connected for long. I called my ISP and they took control of my laptop, changed settings to try to fix it, but it didn’t work. I’ve tried a lot of different things that I can’t really remember but nothing has helped.

I have a Lenovo G500s
I'm on Windows 8.1