"Roger Johnson" wrote in message
news
youtube-dl.exe - System Error
The code execution cannot proceed because MSVCR100.dll
was not found. Reinstalling the program may fix this problem.

All I did was download this executable & double click on it to get that!
https://youtube-dl.org/downloads/latest/youtube-dl.exe

What Windows 10 program am I supposed to reinstall and how do I do that?

Try this:
https://www.onlinevideoconverter.com/en/video-converter