Help me please!

Hey guys, I need some help. I'm having this problem when I go to my desktop by pressing the windows button on my keyboard then pressing the very bottom right of my screen which takes me to the desktop and sometimes when I click back on flight simulator the screen is flashing black really fast. It's like an old projector where you can partially see the plane or whatever i'm looking at for a second and then black flash and so on... Is there anyway to fix this problem like turning on VSync or something? Thank you all in advance.
I've been trying to do the same dam flight from ksfo-klas for 6 hours now and I can't because I end up getting the black flashes! Help!

did you try alt tab ?

Simmer
www.arenalogic.com