This page is fairly technial and it is assumed that you are familiar with reading and editing the registry.
 Netscape 4.75 
To begin with, this product contains RealNetworks which automatically connects to the internet without your permission (detected using ZoneAlarm) and continuously hits the registry (this is guaranteed to slow down your system).
It also loads AOL Instant Messenger and something from U.S. Robotics. It adds 21 new file extensions, mostly for RealNetworks.
There is also a design problem - one of the registry entries is wrong.
HKCR\NetscapeMarkup\shell\open\ddeexec\Application\@="Netscape"should have a value of NSShell, not Netscape. Because of this, every time you double click an html file, you will get a "file not found" error. (Way to go Netscape :) Don't you test anything.) If you try to open a second file, it simply won't display. (What a piece of ...) At any rate, a simple registry hack will fix it. (Yes, I tested it ... but only on NT 4. Oh, well:)
The InCtrl file for loading Netscape 4.75 is 191 Kb, of this 163 Kb is just the registry changes. 45 Kb after most of the RealNetworks crap is removed. With some additional cleanup, I've kept 38 Kb for reference.
One of the more insideous changes (hey, there is a reason that I call this BrowserWars) is the reconfiguration of IE.
HKCU\Software\Microsoft\Internet Explorer\Main
  "Check_Associations": from "Yes" 
                          to "no"
  "Search Page":        from "http://www.msn.com/access/allinone.htm" 
                          to "http://home.netscape.com/home/winsearch.html"
  "Start Page":         from "file:///H:/My%20Documents/html/index.htm" 
                          to "http://home.netscape.com"
HKCU\Software\Microsoft\Internet Explorer\SearchUrl
  "@":                  from "http://home.microsoft.com/access/autosearch.asp?p=%s" 
                          to "http://keyword.netscape.com/keyword/%s"
HKLM\SOFTWARE\Microsoft\Internet Explorer\Main
  "Default_Page_URL":   from "http://www.msn.com" 
                          to "http://home.netscape.com"
  "Default_Search_URL": from "http://home.microsoft.com/access/allinone.asp" 
                          to "http://home.netscape.com/home/winsearch.html"
  "Search Bar":         from "http://home.microsoft.com/search/search.asp" 
                          to "http://home.netscape.com/home/winsearch200.html"
  "Search Page":        from "http://home.microsoft.com/access/allinone.asp" 
                          to "http://home.netscape.com/home/winsearch.html"
  "Start Page":         from "http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home" 
                          to "http://home.netscape.com"
| Check_Associations | Keeps IE from reminding you that its competitor is now your favorite | 
| Search Page | Well, if you're @&! enough to use the enemy, at least your searches will now be made via Netscape and AOL will get the advertising revenues | 
| Start Page | Hey I set that value. Now, instead of using my favorite start page, IE will open defaulting to Netscape. | 
It also hijacked the expected extensions
HKCR\.htm Value "@": from "htmlfile" to "NetscapeMarkup" HKCR\.html Value "@": from "htmlfile" to "NetscapeMarkup"Rather than re-write the existing htmlfile parameters, a completely new set of parameters was written.
The https and http open commands were both changed from IE to Netscape. The following advertisements were added to my desktop
AOL Instant Messenger (TM).lnkSimply installing Netscape made a lot of changes, but additional changes were made the first time it was run and additional changes were made after the first re-boot. For instance, ftp and gopher were re-written the first time it was run. Also the http and https icons were changed.
Netscape Communicator.lnk
Free AOL & Unlimited Internet.url
 
 IE 5 
Well, I finally gave in and captured the folling changes.
 
 Setting IE as Your Default Browser 
From the IE menu, select
Unfortunately, this creates a right-click menu which contains no reference to Netscape. Personally, I prefer to have all browsers and several text editors listed in the right-click menu.