I'm trying to figure out why Chaser's window is stuck at either 16:9 or 16:10 resolution. In the game's Options menu, the resolution is grayed out so I have to go to this path: [game folder]/save/users/default.cfg and manually edit the resolution there. But for some reason the game's window size is always around the 1280x720 resolution regardless of what the default.cfg file says. Is there a way to fix this?

The aspect ratio of my monitor is 16:10, but I want to run the game in a 4:3 window since the game was originally designed for that ratio. But for some reason whenever I enable windowed mode in Chaser, it forces the window to be a fixed 16:9/16:10 widescreen ratio at about 1280x720. Is there a way to manually change the window or resize the window?

Yes, this is a big problem. Chaser in windowed mode has a default resolution 640x480. It does not matter what screen resolution you have. Unfortunately, the game takes aspect ratio information from the system, so the widescreen monitor stretched window with Chaser to the sides. This can not be repaired...

But... I have a 16:9 monitor - 1920x1080. But if I set resolution in the game to 1280x960 (4:3) and fullscreen - it works correctly. When the game starts, the screen automatically switches to 4:3 mode. This allows the monitor. But is necessary to set it properly of monitor.

See what your monitor offers for options. Adjust the setting in the monitor so that the aspect ratio information take from the application. If it allows your monitor, then you can play Chaser in 4:3 and "fullscreen". Like me on this video: https://www.youtube.com/watch?v=-li6M720EyM ;-)

Sorry for my bad english...

Unfortunately, running it in fullscreen does not help my situation. I much prefer to run games in windowed mode so if the game freezes or crashes it doesn't take down the whole operating system. I was hoping that there was some way to manually edit the window, but I guess the game does not allow that. But thanks for giving me information about the game!