Question: Opening the command prompt ("cmd") on Vista into full screen causes the application to take up 100% vertical space, but only about 50% horizontal. Is there not a way I can make this fullscreen? If it's simply not possible, what is a good replacement?

Answer: 
It’s a graphics driver issue. Vista uses hardware acceleration for the desktop, which is why the graphic card cannot switch to text mode (the system would lose track of the desktop). If you have an older VGA that doesn’t support Direct X 10, you should be able to use fullscreen text mode.
You can use [ConEmu](https://conemu.github.io/en/Downloads.html) for `ALT`+`ENTER` fullscreen:

[![enter image description here](https://i.stack.imgur.com/pvTno.png)](https://i.stack.imgur.com/pvTno.png)