Just FYI internet explotrer is NOT a internet "provider" as you eluded to. Internet explorer is simply a web browswer interface just like, firefox, mozilla, firefox, chrome, safari, etc).
Internet explorer is one of the compatible browswers and also recommended for use by sling. To get a better "viewing experience however (expecially from remote locations), move the ISP's bandwidth package up to a higher package in terms of upload speed. This is done by contating your "I"nternet "S"ervice "P"rovider (comcast, charter, at&t, verizon, etc....)