There are a few requirements for putting a course online. As with all things computer, there is a wide range of options. Minimal resources will do the job, but better resources make the job easier. Here are my recommendations.
Any computer can do the job.
However, the more processor power, RAM and hard disk memory you have the better you will be able to do the job. I have successfully done HTML programming on a 386 portable with 4MB of RAM, however it is much better to have more machine available. A Pentium running Windows 95 or NT and at least 32 MB of RAM is preferable. It is often necessary to run several programs at the same time. I usually run a browser, an HTML editor, Windows Explorer and WS FTP all at the same time.