Sometimes IPv6 is installed on XP in a hidden form — sometimes IPv6 may be installed, but not visible in any Windows GUI. To find out, go to command prompt and enter:
netsh show helper
If IPv6 is installed, in that list will be “ipv6”. To uninstall on XP, run this:
The ipv6 command does not exist on Server 2003. The following does:
netsh delete ipv6mon.dll
Hidden IPv6 has been shown to cause problems in some Oracle environments.