Zero Hour freeze when click on other screen (or alt tab)

Hi,

I bought the game "command and conquer Generals zero hour". I use windows 10 with 2 screens, very often (50%) when I click with the mouse (accidently) on the other screen (non game screen) when playing, the game will freeze and will also freeze my entire windows. I can't event access the task manager to kill the process. only option I have is ctrl alt del and restart pc.

Can you please help?

Thanks,

Barak.