By default, Vista installs without telnet program. But you can active telnet and use it.
Follow these steps
1.Open My Computer
2.Click the Uninstall or change a program.
3.In the left Task pane , select ‘Turn Windows features on or off’
4.Click continue ,When display UAC dialog box.
5.Select Telnet client check box.
6.Ok ,and waiting for some time.(Time depends your hardware configuration)
7.Close window and open your command prompt.
8.Type Telnet , and Enter.
--