you could have a black background with your task bar on another screen, and run tf2 with windowed with no borders.
forgot fullscreen - also lyna's method won't make it 1024x768

Not sure if anything else would work, hope you find a way though

cant you do that with -w and -h commands in tf2 properties? It would have to be windowed mode though.

I don't mind having it in windowed mode, but I thought you couldn't stretch the game without having it full-screened?

I feel like it is not possible. You would need a 16:9 resolution, and if using windowed mode, it needs to be the same width as the monitor, otherwise TF2 will not use all of the screen, and you can't stretch the window (assuming noborder, don't know about with). Even in fullscreen this can be hard to get right; the auto-scaling in the Nvidia and AMD drivers don't always work perfectly.

solution: run in 1280x768, use black tape on the top and bottom of your screen

The only reason I think this is possible is that NVIDIA has some scaling option where you can set the monitor to a certain resolution and have black bars on any of the sides. The only problem is that when I launch TF2 it just overrides the desktop settings and forces it back to my native res.

Let me get this straight, you want to make the aspect ratio be 4:3, and have it stretch to the sides, or do you want 1024x768 specifically.

i want the game's aspect ratio to be 4:3, but I want to stretch it out to a certain extent (in the case of my monitor, i would want it to be stretched to 1680x945)

gotta have dat extra fov
I've wondered if this is legal for ESEA

ATI or NVIDIA?

ghetto way would be windowed mode tf2 and set the desktop native resolution to 1024 x 853, have a black wallpaper.

stretching windowed mode will require stretching the desktop resolution using scaling. are you trying to replicated the settings you had at lan at home?

1024x768 would decrease his fov

You might want to try switching the "Perform scaling on:" option to GPU.

enable gpu scaling in gpu drivers and play in fullsceen

Wouldn't playing at fullscreen (or fullscreen windowed), default res -sw -w 1680 -h 945 and fov_desired @ 75 give you a similar result?

(Read the question wrong first time).

You might have an extra 5 degrees or so of FOV over what you're going for, but it's pretty close.

Look in your monitor's OSD menu for something along the lines of: display with aspect or stretched option.

You might notice extra input or display lag if you use a non-native resolution though.

Why?