Deciding what services to run on a host involves sometimes difficult choices as you try to balance users' needs for services against security. Refer to this list of port-to-service mappings. You will have to make choices about which services to keep running and which to turn off.
Note: If you give the command netstat -alnptu (Unix) -or- netstat -abno (Windows) will provide you with a snapshot of your current network connections, which may help in understanding what you need to turn off.

UNIX hosts
Service Command to turn OFF serviceCommand to turn ON service
chat (ircd) sudo /usr/local/share/unreal/unreal stop sudo /usr/local/share/unreal/unreal start
name (named) sudo service bind9 stop sudo service bind9 start
ssh (sshd) sudo service ssh stop sudo service ssh start
ftp (vsftpd) sudo service vsftpd stop sudo service vsftpd start

Windows XP hosts
Service To turn OFF serviceTo turn ON service
web Start > Control Panel > Add or Remove Programs.
Select "Add/Remove Windows Components"
Uncheck "Internet Information Services (IIS)"
Select "Next"
Select "Finish"
Start > Control Panel > Add or Remove Programs.
Select "Add/Remove Windows Components"
Check "Internet Information Services (IIS)"
Select "Next"
Select "Finish"
Remote
Desktop
Start > Control Panel > System
Select the "Remote" tab
Uncheck "Allow users to connect remotely to this computer"
Start > Control Panel > System
Select the "Remote" tab
Check "Allow users to connect remotely to this computer"

Windows Server 2003 hosts
Service To turn OFF serviceTo turn ON service
web Start > All Programs > Apache HTTP Server 2.2 > Control Apache Server > Stop. Start > All Programs > Apache HTTP Server 2.2 > Control Apache Server > Start.
Remote
Desktop
Start > Control Panel > System
Select the "Remote" tab
Uncheck "Allow users to connect remotely to this computer"
Start > Control Panel > System
Select the "Remote" tab
Check "Allow users to connect remotely to this computer"