Hi Kovid. Excellent software. Truly excellent. Thank you for birthing, and maintaining it.
I had this problem before. I only run 64 bit Calibre.
See this thread:
https://www.mobileread.com/forums/sho...96#post2836696
Each time I download the latest version (2.1), though the download file is named 2.1, it is actually the 2.0 installer. I've downloaded the 2.1 installer from FossHub; from the default Download page; and from the Previous Releases page.
Every time I download I get the 2.0 installer.
I use Firefox. I deleted all history, cleared cache, and tried again. Still 2.0 installer.
I installed the Download Statusbar add-on for Firefox; still 2.0 installer gets downloaded.
Just for kicks I downloaded the 2.0 installer from the Previous Releases page and compared the MD5 hashes. They match for every installer I downloaded today. That is to say, every supposed 2.1 installer I downloaded this morning has a hash that matches the 2.0 installer.
Now I'll try downloading on Chrome and see what happens.
Edit:
Unlike the OP I do NOT get the "The specified account already exists" message when I attempt an install. I get the Repair/Remove dialog.
I am running Win 7 Home Premium 64bit on an Intel Core i7 machine.
I duplicated the issue on my backup machine AMD64 running Win 7 Home Premium. I had not yet upgraded from 1.48 to 2.0 on that machine. When I downloaded and installed the"2.1" installer, the first message I get on opening is "New version 2.1 of calibre is available for download."