1) Before uninstalling Netscape make a backup of your profile data
2) Remove Netscape Communicator via Add/Remove Programs inside the Control Panel
3) Delete all files and folders resulting from a Find for the word Netscape
4) Delete nsreg.dat and liprefs.js (do a Find for these as well)
5) Click on Start - Run and type regedit.exe and press Enter
6) Delete the following Netscape registry keys:
THIS IS VERY DANGEROUS!!!!BE CAREFULL !!!!IF YOU MESS YOU COMPUTER UP HERE-YOU ARE TOAST!!!DO NOT SAY I DID NOT WARN YOU!!!
HKEY_CURRENT_USER\Software\Netscape
HKEY_LOCAL_MACHINE\SOFTWARE\Netscape
HKEY_USERS\.DEFAULT\SOFTWARE\Netscape (not everyone will have this key)