Proxy Server Isn’t Responding on IE

I had an issue with my Internet Explorer. It won't run and it always shows an error about proxy server. The last time I run my browser, there is no issue found and I can very well use it without problems. Today, when trying to open it, the error states, "The proxy server isn't responding. Check your proxy settings". What is the cause of this issue? Do I need to reinstall or remove my browser and switch to Chrome or Firefox? Please help me.
