So, you're using Netscape Composer, right? I believe it's quite old. I suggest you find something more current to work with. See
The 10 Best Free HTML Editors for Windows for a list of free editors. The only HTML editor on that website that I have actually used is Bluefish and I was using it with Linux, and this was a few years ago. So, I can't really give a strong recommendation for a particular editor because I haven't used any of them for awhile.
I do maintain a website for a local organization but I use the cPanel provided by the hosting service and edit pages by using one of several editing modes available via the cPanel. Most hosting services provide the same tools, so, if you have a hosting service for your website, I suggest you take a look at what HTML editing tools are available from them.
And, if you have some knowledge of HTML, you can use just use Windows Notepad to edit your HTML files, test them by opening the HTML files in your web browser, and then upload them to your web server.
Knowing more about your level of knowledge would be helpful.