Are you using the bundled graphics driver, which may be optimised for gaming ? You may need a generic driver from the chip-maker eg Nvidia...

Thank you !

My bad. It was very, very late, and 'Robbie the Ratter' aka '005½' had just returned from her 3AM feline patrol soaking wet, demanding food and fuss...

I used to craft Medieval-ish scenes with TurboCAD, FloorPlan and Poser 4, but have been out of CAD for a decade.

Returning, the budget version of TC still has its 3D Boolean legacy bug. The FP version is now too complex, too restrictive, and lacks back-compatibility.
{Grumble, Grumble... }

Plan_B ...