Thanks to the people who helped me, now I can remotely startup and shutdown
a system in my network.

It is necessary to enable the option "wake on lan" / "wake on PCI", or
whatever it is, in both : BIOS and network device properties in control
panel--system.

And then I must use this utilities : (freeware)

To startup the remote system :

MC-WOL mac_address

http://www.matcode.com/wol.htm

To shutdown the system :

PCTools Utilities :

PSSHUTDOWN -k \\computer_name

http://www.sysinternals.com/ntw2k/fr...shutdown.shtml

thanks