Hello,
First of all, thanks for providing the software. Looks very well, works great, admirable.
I will donate in any case, as soon as I finish writing this post. But before I do that, I also wish to register a complaint about this parrot.

It's stone dead.
In other words, Calibre appears to be one of those programs, which require original installation exe to uninstall old versions.
Please, please, please, I beg you to see your way to fixing this. It is ugly as hell; no sane person wishes to clutter their harddrive with installation media for programs downloaded from the net.
Since my last use of Calibre was quite some time ago, I even am not sure, if I *can* redownload original installation exe for that version (3.11.1 64bit WIndows). It is a problem not unique to Calibre, but is definitely annoying as hell.
To quote Stack Overflow on this problem (
https://stackoverflow.com/questions/...ut-an-msi-file) :
"It is not normal or standard MSI behavior to ask for the original source media - it indicates a badly designed MSI package. If you experience this with a vendor MSI it is highly recommended that you report the problem to their support team."
Cheers and best regards,
~G