A driver is trying to be installed on my pc by itself?

Let me first start by saying that I access the internet via unsecured wifi at my apartment complex. Lately I noticed that my computer was running slower than normal so I immediately ran my Webroot Internet Essential for any viruses and check my firewall. Then all of a sudden, I noticed that my PC said it detected a driver and requested my permission to install it? It was an X-Box 360 controller driver, the problem is I don't have an x-box controller hooked up to my pc. So, I deny the permission of coarse. Then, maybe like 2 hours it stated that it detected another driver that will allow me to share my media with that other person? So, I came to the conclusion that someone is either trying to access my PC or hack my PC or something of that nature. Can anybody tell me how to block this??