Installed NS 7 from CD using ramona's advice (although some links to her site did not go through when I later tried them). Uninstalled 6.23 and custom installed just the barest parts of NS 7 tonight.
So far, everthing works well.
I'm running NS 7 under Win 98 SE.
UserAgent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0 (nscd2)