How to connect to the Internet without proxy software?

Hi, I have a problem with connecting to the Internet via Windows 7. Some days before, I had a proxy and was using it, but it does not work correctly. I deleted it but I cannot connect to the Internet without any proxy after that. I had to run a proxy software and then can connect, so how can solve this problem. I want to connect to the Internet without proxy. What should I do?

I opened Mozilla>Tools>Options>Advanced>Network>Setting and check No Proxy, and then try to connect to the Internet, but it did not work What can I do?

please help. I am so confused

Thank you so much. I did it but it did not work again and showed the previous error but when I run the proxy software, the website opens correctly. So, what should I do now, please help. Thanks.

I am using a cellphone internet and tethering, and then try to connect to the internet via laptop. I am pretty sure that it is because of the proxy software, because when I run it, the problem solves.

I cannot. I have only cellphone Internet. I always use it with no problem. What is ISP :)

Thank you.