Hi,
If it is in another location than the default one it is the same error than that thread :
https://www.mobileread.com/forums/sh...d.php?t=341933
My workaround is stop install calibre in another directory than the default location.
Other one seems to do a link from the default location to the one you want.
The library can be elsewhere, only binaries need to be at the default location for the installer to work.
It seems something change in windows some time ago that impact the installer and the way it works.
Regards