Get that splash screen disabled.
Try launching from the command-line:
Try launching in gui debug mode via command-line:
If you get it to go; disable the splash screen in the preferences.
If worse comes to worse ... find the line:
Code:
"show_splash_screen": true,
and change it to:
Code:
"show_splash_screen": false,
in the %APPDATA%\calibre\gui.json file.