[jamesgl]

Okay… Back from visiting the kids and the grandkids.

Merry Christmas to BR, and everyone else who is possibly following.

I uninstalled the Wacom tablet driver, unplugged the tablet, which happens to be an INTUOSpro small tablet.
Both uninstalls were done using the control panel/programs and Features/uninstall etc..

I uninstalled the Logitech set point.
I restarted the computer in safe mode.

The 64-bit Calibre application does exactly the same thing.
It locks up when you try to use either of the Add Book or save book to disk functions, and in the safe mode completely disappears – self closes – after about twenty seconds or so.

You cannot use the add book function.
You cannot save to disk.
You CAN read a book using the internal book reader.
And you can convert from EPUB to say Mobi. I have not tried other conversions to see if they work.

To my untrained eye the problem appears to be present when you attempt to access the disk to either read or write .

Again in the SAFE MODE – 64-bit will not run Wacom and Logitech drivers removed..
32-bit runs normally with both drivers – Wacom and Logitech removed.

Hope this helps establish a diagnostic course.

jamesgl