Right click on the file and choose "open with". The top off the list would be your PDF program. Wrong as you know. Windows will give you 1 choice so click on "more apps ". Choose windows Explorer. Should open with this. Or download the free zip app from the Mocrosolf store. Once installed choose that to open the rar/wip files.
BreeZip is free but it only opens the files or extracts them. It wont pack zip files. But it's free.