i have tried so many tools,power off,shutdown from dos command,remote shutdown.but it's useless.

when i typed shutdown \\aaa bla bla bla..access is denied.
my network is like i have one wireless router,my laptop and my brother laptop and desktop connect to this wireless router. sometimes i need to power on the desktop coz some of my data is in there(i don't have enough space in my laptop to put all data in there),but since the...