XNA game resolution higher than pc resolution - Does it cause problems?

Question

When developing a xna game for pc, one problem is that people use different resolutions.

But what happens when the target pc has a lower resolution than the game? Do I have to use vector graphics?

The only way to use a lower resolution is by making the view port smaller, but I don't want to do that. I tested setting the resolution to ultra hd but it stays on full hd on my full hd screen. Is full hd just the maximum of xna or does the game automatically use the screens resolution when it's lower?

The game runs on fullscreen.

Answer 1

A common solution to this problem is to always render one's game to a set resolution and then scale the entire screen image to fit. Examples of how to do this can be found at XNA resize window without increasing resolution