You mean "abd is not recognized as an internal or external command, operable program or batch file"?
That means it cannot find the file, probably because one of the following reasons:
- You simply mistyped it. It's "adb" (for "Android Debug Bridge"), not "abd". There should be a file with the same name in the folder you downloaded.
- The command prompt isn't running from the folder with the file. It won't find all the files on your system, just the ones in the current working folder, which is displayed at the start of every line. You can change it with the "cd" command. For example, if you're in "C:\” you can type "cd Users" to go to "C:\Users".
- You're not using the command prompt. I'm assuming you're on Windows, then make sure that you're actually using the command prompt by starting "cmd.exe". If you're unsure, just type that into the search and click the first result. If you accidentally started PowerShell, another terminal program on Windows, my tutorial might not work because it has a slightly different syntax.