I have three machines at home two of them are windows one of them is mac os and i want to share the one keyboard one mouse and two screen with all of them how can i do it
One approach could be installing VNC server+client packages on all 3 machines (like RealVNC or TightVNC) which would allow you to remotely access one from another.
Then play with the configurations to see which one matches your usage better (i.e. which machine should be driving the actual hw and access the other 2 machines via VNC). I'd start with the mac driving the hw :)
Won't be fast enough to play action games or watch videos, but it can be great for other stuff. Not sure if you'll be able to configure 2 remote displays - I never tried.
Of course, you may still need to hook up real hw once in a while if/when the machines get stuck at boot and don't make it to the point where the VNC server allows remote access.
There may be even faster similar sw out there, I didn't look as VNC worked decently enough for my usage.