Please stop the virtual machine by navigating to Actions -> Stop in the virtual machine menu on the upper left, open the virtual machine configuration window, navigate to Hardware -> CPU & Memory and allocate 2 processors (or just 1 if the total number of available processors is just 2) and 2 GB of memory for Windows [or just 1 GB if total Mac memory is only 2 GB (or) 3 GB if total Mac memory is 8 GB (or) 5 GB if total Mac memory is > 8 GB]. Then, select 'Graphics' and allocate 1 GB of video memory for Windows. Finally, ensure that 'Vertical Synchronization' is enabled and '3D Acceleration' is set to 'DirectX 10' under 'Advanced Settings'. Then, close the window and check for the issue again.