I'm not entirely sure why stuff like this is happening, bogus antiviruses etc. You'll have to look into it yourself. Did you recieve a rar file with it's contents? If you can send a screenshot of what application you're opening perhaps I can help.
Umm, try to extract it to an already designated folder? If you trying to open an downloaded file, but not the extracted. I dunno, maybe you accidently made your PC open RAR files as notepad? I have similar shit, but with file that need Adobe to run, or similar program.
