Trouble starting Calibre on Windows 10

I upgraded from Win 7 to Windows 10 and then upgraded Calibre to 2.44.1 and now Calibre will not start. It is reporting that I´m on XP! (well that was some time ago...) The error message translates to something like:
Error: Windows XP not supported Calibre version newer than 2.0 cannot be run on WinXp...

Does anyone know how I can fix this or run Calibre anyway as I´m not on XP...

:blink: