How much RAM is installed on your host?
Anyhow, I recommend you to reduce the number of CPU to just 2 or 1 .
Reduce the RAM from 12 GB to 4 GB ( unless you really need 12 GB for your Windows guest ) .
Also, change the compatibility to 10 ( currently you are using hardware compatibility of 7 )
If the issue persists, disable 3D acceleration for the guest
Cheers!
Avanish