For some security reasons for your Server to be offline from the network at any specific time or to prevent some computers on the network from accessing the internet, you can disable the DHCP (Dynamic Host Configuration Protocol) from the Service management console or using this command line.
-Command line to Disable DHCP Service:
net stop dhcp
sc config dhcp start= disabled
-Command Line to Enable DHCP
sc config dhcp start= auto
net start dhcp
You can copy and paste into Notepad then save it as .bat