Sometimes you need to access PCs on a network remotly.You can use the
Remote Desktop feature for this.To en/disable the acceptance for Remote
Desktop Connections on the given PC navigate to :

Note:This can be done through network registry as well !

- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Control\Terminal Server\

Locate now in the right pane the entry :
fDenyTSConnection

(it is a REG_DWORD [DWord Value] entry,just in case you need to create it)

Doubleclick the mentioned entry and set it's value to :
0 (Remote Desktop enabled)
1 (Remote DEsktop disabled)

Reboot your the PC.

Note:If you access the PC through network registry type a
shutdown -m \\hostname -r   in a command prompt.This will reboot the
affected PC through the network.The PC will now listen on the default port
for any incoming Remote Desktop Connections.