files originally saved as .pdfs are now showing as .pdf.xml and will not open

  Some years back I saved some pdfs to usb drive from my work computer -- the files saved and displayed as pdfs.  Now, when I try to access the files on my various Windows computers at home, file explorer shows those files with .pdf.xml suffix instead of .pdf.  The files were originally saved as pdfs.  I cannot open these files despite trying to use Adobe Acrobat, various Windows browsers (Chrome, etc).  I have tried renaming the files to .pdf, eliminating the .xml suffix.  I have tried opening the files in Word.  Nothing works.