***EDIT OF MY PREVIOUS MESSAGE***
I went to the download page to get an older version that I could use while I wait for a solution.
So I clicked on
"Previous releases of calibre are available here" and I found out there is a 64-bit version of 5.5.0 there. On the main
Windows download page, the
Download Calibre link automatically sends the 32-bit file.
I installed this 64-bit version of 5.5.0 and Calibre works perfectly now
