Here's a trick I just did that is more appropriate with two monitors. Download Code Blocks and use it's editor to hold a historic version of any codes as needed with a copy and pace, each tab can be used to hold code for comparing. Also it has nice settings for changing colors to highlight (red for comments, etc.) This corrects the problem that Visual Studio 2017 can only run one branch even if two studios are running. I haven't seen Visual Studio 2019 yet. There's also a need for disabling the spell checker in the plugin section, and reloading Code Blocks (eliminates red squiggles).
Josheir
Edit: all put this in the beginner's section too.