By default windows comes out with a Telnet client... all you do to open this is this:

Start>> Run>> Type "cmd">> Enter>> Type "Telnet">> Enter. There, telnet will open. Telnet is a utility used for remote connections, a remote emulation tool. The format of the commands are simple...

Type this in:

open [Target IP] [Target Port]

the Target IP will be example
the Target Port will be Example 21

Common Port names and number are:
Service name Port

FTP(File transfer protocol) 21
SMTP(Simple mail transfer protocol) 25
HTTP(Hyper Text transfer protocol) 80
SSH(Secure Shell) 22
Telnet 23

and then which ever ports are open after your port scan.

get haktek to port scan, there are alot of other tools, on page 1 of this forum at the top there is a sticky note with all those sites that can be useful, but dont forget about G4EF.