Many of us have found it easiest to write our reply on whatever word processor we use, then block it with the cursor and use the edit facility to copy to Windows clipboard. Next start up your Internet whatsis, click your way into the post part of BOL, and use the copy part of the edit menu to place the whole message in the little box (which stretches to receive the file). That way you make sure the message is safely on BOL before you erase it from your hard disk.
Do, however, download Netscape 3 from their website. It is much much better than 2, even though they're trying to get us to use the beta version of 4, which from its reviews does not seem nearly ready for consumer use.