Internet Explorer is opening everything

Hello, my computer now uses Internet Explorer as the program to open all of my files. All of my icons have become the internet explorer icon and I now am very limited to what I can open and how. Rainmeter for example won't open and every time I turn on my computer something pops up that says view and track your downloads yet the options to open or save do not work. I am pretty sure I know what I did to cause it, I just have no idea how to fix it. I downloaded something in a WinRAR and then couldn't figure out how to open it so I chose to - open with - internet explorer and since then I have had this problem. I think I need to switch what everything opens with back to its default but 1. that could be totally wrong and 2. I have no idea how to do that. I am not very adept with a computer so I would appreciate details in explanations please. Thanks.