My Question clarification,
What I kind of want is, through one machine, one OS....
I wish to divide the operation in two. Do you guys understand what I am seeking?
You can certainly have two windows/apps active, one on each monitor. The problem is that there can be only one cursor per OS.
If you had two mice connected, either could move the cursor which would be a real contention issue between the two users.
The same would be true of a second keyboard.
In the interests of domestic tranquility, consider getting your spouse their own PC.