Hi Bob
Welcome to the list. i am very surprised that nothing on Win 10 pro will open the MD files. You don't even get a dialogue box asking which app you want to open the files with? Here's one way you might do what you want.
There is NotePad++ which can be found at:
I think you will first need to install a LaTeX distribution before you can convert to PDF. Sorry distribution may not be the correct word but just cannot think of a better one at the moment. MicTEX is apparently a good choice for Windows and can be found at:
I do not know anything about creating a batch file in Windows, but you could install GNUMake which has a Windows version. I think it only works in 32-bit mode though:
After installing GNUMake, you could create a 'makefile' in the directory where your MD files are and try creating the following file.
test.pdf: <filename>.md <filename>.md etc
pandoc -s -o test.pdf <filename>.md <filename>.md etc
You will need to tab once before writing the pandoc command, for some reason MAKE doesn't like spaces. I am not a mAKE expert and there may be a better way of accomplishing this.
Once you've written and saved your makefile go back to Windows Explorer and open a Windows Powershell session or Command prompt session from the File menu. (This will open either at the folder you are currently in).
Type the path to GNUMake, it might be something like:
C:\Users\Bob\Program Files\GNUMake\bin\make.exe
Type a space and then the word 'make'. This should hopefully build your PDF file, merging all of the MD files into one PDF.
HTH
James