The Technofile Web site has moved. But it sure can use one. If you don't have one on your system, you're missing out on a lot. In the bad old days, the only way to get certain things done when a computer booted up was through two files stored in the main directory of your boot disk. Lord only knows why two files were needed one would have done nicely if Microsoft had changed the way DOS works but some things are just plain never going to be explained.
Batch files are just lists of commands.
Type a command on a line in a batch file and the PC does whatever the command says. Ah, here's where Microsoft laid an egg. It's not a SYS file the way nearly all other SYS files are. It, too, is just a list of commands It, too, is just a text file that has instructions for the computer, line by line. So that's the first thing I want you to remember.