Do you have a PDF reader? These documents might be PDF so if you go to control panel, default programs, set associations (Associate a file type or protocol with a program) then let it populate. Scroll down to .pdf , left click and then select the Change program.. tab top right. You should get a pop-up with choices and a link for more options. Select your PDF reader.
Surface Pro 5 News - release date, UK price, features, specs