how can i use telnet command for my pcs and router.
i am using winxpsp2

To open Telnet

Press Start > Run and type cmd then click ok.

Type telnet then press enter

telnet should be enabled on the target host. if it is, just run "telnet targethost/targetIP"
if you want to connect to a specific port, just add it's number after the targethost.

i cant connect normally if iam using telnet command

well, that means there's either a firewall in the way, or the hosts you're connecting to do not allow etelnet connactions because they don't have the service running

xp home does not have a telnet server

and telnet is not secure

using without antivirus
even the service is running

use telnet O then port number or ip address then press enter