(This also works for Fallout 3 from what I've seen)

Now someone else may have already made a guide on this, but I wanted to post it here just in case.
So recently, I started playing New Vegas, and the mouse acceleration really got to me, so I found a way to fix it.

Go to your New Vegas install directory (this varies, but the default location is in the steamapps\common folder), and find Fallout_default.ini. Just using fallout.ini works too. Open it using notepad, and scroll down to the section titled [Controls].
There, paste the following:

fForegroundMouseAccelBase=0
fForegroundMouseAccelTop=0
fForegroundMouseBase=0
fForegroundMouseMult=0

Below these options, you should also see an option called 'bBackground Mouse=0', change this to a 1. If you have followed the steps correctly, your ini file should look like the image below.

Be sure to also check your "My Games" folder for Fallout.ini. By default this should be at "C:\Users\(Your Username)\Documents\My Games\FalloutNV\Fallout.ini" and add the same lines that you added to the other ini. (Thanks to Blue-Ice [161] for this fix)

And THEN, you can open the game and enjoy. This should fix all issues involving Mod Organizer 2, at first when modding the game again earlier today, the tips in this guide just didn't work for some reason. But after a bit of tinkering with ini settings I found a solution.


If you have any more issues with the game please don't hesitate to ask in the comments. I will try my best to help anyone who needs it.