What do you have for video out on the PC?
Both displays will be 1920x1080 and identical views?
If you have more than one graphics port you could do dual monitors, one vga one hdmi for instance, and duplicate or mirror them; but that will tax the computer system (some).
If you have HDMI, the easiest would be hdmi duplicator and extra long HDMI cable ($1/ft), provided you can run the cable. No load extra load on the computer.
There's HDMI over ethernet extenders (I use them) but cost could be a wash depending on the extender, buying cable(s), shipping ... still need to be able to run the cable physically.
Beyond that, HDMI duplications and wireless HDMI may be an option if you can't run cable, provided you have good wireless transmission throughout the wall(s) if you need to go through them.
So there are some options. Solutions and being easy really depends on physical circumstances and then budget.