Installation and Profile

Important Information about the user.js
Netscape's new super-configuration file is a plaintext file called user.js. Netscape itself still uses the prefs.js like previous versions, but the 100% user-controlled user.js has precedence, that means any entry in user.js replaces any similar entry in prefs.js. Netscape on the other hand does not have the right to manipulate user.js, that means it will not be overwritten or changed by Netscape in any way. That's why changes to user.js can be made while Netscape 7 is running.
User.js lives in your profile directory . Usually user.js is not there when you install Netscape, it has to be created using notepad or any other plaintext editor. Nearly all tips described here use the user.js, so you might as well create the file now.
Typical mistakes regarding the creation of user.js:
- wrong file name extension (Windows' default way of displaying known file types is without the extension, so if you create a user.js with Notepad be sure it is called user.js and not user.js.txt)
- user.js is not a plaintext file, because you created it with Word or a similar program.
Here's an example of a user.js file

Install / reinstall / add components

The following takes Netscape 7 as an example. It works the same for Seamonkey and Firefox—simply find the appropriate files on the Mozilla server (ftp.mozilla.org)
All Netscape 7 (for Win32) components can be found here (change the path for your language/OS/Netscape version): ftp://ftp.netscape.com/pub/netscape7/english/7.02/windows/win32/eehxkt/
You can add or reinstall components any time.
Example:
You decide to install Net2Phone after all (you really shouldn't - trust me on this, but for the sake of explanation). Go to the ftp directory and click on the file n2p.xpi, Netscape 6 should commence the installation.
Here's a list of the more important components:
artext.xpi - AOL ART extensions
browser.xpi - the Netscape 7 browser
flash.xpi - Macromedia Flash
hpprint.xpi - HP Printer tool
jre104_01i.zp - Java 1.4 Plugin
jre104p.zip - Java 1.5 plugin dll
langenus.xpi - US-english user interface
mail.xpi - Netscape mail/news
n2p.xpi - Net2Phone
nim.xpi - Netscape Instant Messenger
psm.xpi - Personal Security Manager
nsrp8.zip - Realplayer 8
skinclas.xpi - Classic Skin
spellchk.xpi - Spellchecker
talkback.xpi - Netscape Talkback tool
xpcom.xpi - XPCOM (when you have problems with xpcom)
winamp.xpi - Winamp including Netscape Winamp Skin

Netscape 6.x/7.x: Deactivate the "Activation" process

There are many ways to accomplish this. The easiest way is to delete or rename the file activation.dll (found in \Netscape 7\components).
A more sophisticated way would be to go to your Netscape\Netscape 7\defaults\pref folder. There, open the file all-ns.js with your favorite text editor and find the following entry:

pref("browser.registration.enable", true);

Set this to false and the dialogue is gone.
You could add this line to your user.js as well, but in this case it doesn't make much sense, since you want to get rid of the activation process completely, not just for one profile.

Transfer your Netscape 4.xx profile data manually

Bookmarks:
Copy bookmark.htm from your 4.xx profile directory into your Netscape 7 profile directory and rename the file to bookmarks.html.

Mails:
Copy the mail files (the ones without extension) from your 4.xx mail directory into your Netscape 7 mail directory, for example
C:\Program Files\Netscape\Users\YourProfile\Mail --> C:\Windows\Application Data\Mozilla\Profiles\YourProfile\xxxx.slt\mail\mailserver (Profile Location varies on each system, see http://www.holgermetzger.de/pdl.html) - mailserver is the name of your imap/pop mailserver, for example pop3.verizon.com or imap.netscape.com.

Address book:
In Netscape 4.xx, export the address book into an ldif file and import it into Netscape 7.

Cookies:
Copy cookies.txt into your Netscape 7 profile folder.

Installing Java:
Install the Sun Java Plugin . Java should detect your browser and enable Java automatically. If this fails, add the following line to user.js:

user_pref("plugin.scan.SunJRE", "1.3");

If adding this line also doesn't have the desired results, you have to copy the java plugin files manually:
For Java 1.3:
Go to C:\Program Files\JavaSoft\JRE\1.3.1_01\bin\ (or whereever you installed the Java Plugin) and copy the following files into your Mozilla/Netscape 6 plugins directory (C:\Program Files\Netscape\Netscape 6\plugins\ ):
NPJava*.dll
NPOJI600.dll

Netscape 7: Installation fails: "netscape xpcom:-207 cant_read_archive"

You likely installed Service Pack-1 for XP recently. Use Windows FIND feature to locate a file named ZLIB.DLL in the Windows program directory. There may be other files by that name elsewhere. Rename this file to ZLIB_DLL.OLD. Then install NS7.

Netscape 7: The program won't run after installation

Problem: Nothing happens when you try to start Netscape.

This is a problem with conflicting files in c:\program files\common files\mozilla.org

Try the following:

Uninstall Netscape (or any other Mozilla suite version you have installed)
Delete C:\Program Files\Common Files\mozilla.org with Windows Explorer (or your favourite file manager)
Reinstall Netscape.

Transfer your Netscape 3 profile data

Netscape 7.1 can't automatically import your profile data from good old Netscape 3. But that's no biggie, since Netscape 3's files are basically similar to Netscape 4. All you have to do is copy your profile data to your Netscape 7.1 folder.

Note #1: You can't copy specific settings (for example mail server settings), it's only possible to transfer the "raw" data.
Note #2: Probably easiest way to make a transfer to Netscape 7.1 is to install Netscape Communicator 4.

Netscape Communicator 4 will import your old Netscape 3 files completely. And Netscape 7 will be able to import from Netscape Communicator 4. But Netscape Communicator is a huge download, and modem users might want to do a manual profile transfer.

Manual transfer of the most important files:
1. Locate your Netscape 7 profile directory.

2. Locate your Netscape 3 profile. Default place is C:\Program Files\Netscape\Netscape\ - Netscape 3 doesn't use individual profile folders, so your stuff is actually in the program folder.

3. Bookmarks: Copy bookmark.htm from Netscape 3 to the Netscape 7 profile folder and then rename it to bookmarks.html

4. Mails: Change into the \Mail\ subfolder in Netscape 3's directory and copy the files to your Netscape 7 Mail subfolder, I recommend toe "Local folders".

5. Address book: Import the address book with Outlook Express. Then import the Outlook Express address book with Netscape 7 ( Address book -> Tools -> Import)

Linux/Unix: Enable font smoothing
By default, Netscape 7.1 does not use font smoothing in Linux. To enable this read this howto.

Share the same profile across different Windows accounts/Windows versions
If you use different Windows accounts or dual-boot different Windows versions you probably don't want to create and set up a profile in each version (time-consuming process). Instead, share your profile information across those accounts/Windows versions.
To do this it suffices to share (i.e. copy) one single file: registry.dat—Mozilla saves its profile information in there.
Examples:
You create a Mozilla profile in Windows 98. You then boot into Windows 2000:
- Start Mozilla one time.
- Close Mozilla completely
- Copy the file registry.dat from its Windows 98 location (see profile information) into the Windows 2000 folder.
E.g: C:\Windows\Application Data\Mozilla\Profiles\registry.dat (Windows 98)
C:\Documents and Settings\Username\Application Data\Mozilla\Profiles\ (Windows XP)

Now start Mozilla again and it should pick up the profile you created in Windows 98.

It works the same when sharing the profile among different Windows users.

userContent.css
For details what you can do with this file, see http://www.mozilla.org/unix/customizing.html

userChrome.css
For details what you can do with this file, see http://www.mozilla.org/unix/customizing.html

Workaround: Install Addons that require a specific Mozilla version
For Advanced users!

Addons use installer scripts that check for your browser version (e.g. Firefox 2.0). If a new version of Firefox is released some addons will refuse to install because the installation routine has not been updated to include this new version—despite the fact that the addon would work just fine. Here's a workaround to force installations of addons. I use the installation of Mouse Gestures in Firefox 3.0RC1 as an example:

Download the installation XPI for Mouse Gestures (mouse_gestures-1.5.2-fx+mz+zm+tb.xpi)
Unzip the XPI (it's a normal zip file!)
Open install.rdf using a good plaintext editor (not Notepad)
Look fore the following:
    <em:targetApplication> 
      <Description>
        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
        <em:minVersion>1.0</em:minVersion>
        <em:maxVersion>2.0.0.*</em:maxVersion>
      </Description>
Change
<em:maxVersion>2.0.0.*</em:maxVersion>
into
<em:maxVersion>3.1</em:maxVersion>
Save the changes you made. Re-add the files into a new ZIP archive and rename it into an .xpi. Install in Firefox.

Be careful: While this works with many addons there's no guarantee it'll work with all of them.

13. Firefox 3: Bookmarks are not picked up from older version
If you update Firefox from version 2 to 3, all your bookmarks might suddenly have vanished or an seemingly older version of your bookmarks will be used. This problem can be solved by deleting to files (with Firefox 3 closed, of course): places.sqlite and localstore.rdf in your profile folder.—Thanks to Rundy B. for the heads-up.