Set WSHShell = WScript.CreateObject("WScript.Shell")
Set oFS = CreateObject("Scripting.FileSystemObject")

strWarning = "Due to network maintenance, this computer must be restarted. You have 5 minutes to save your work from the start of this countdown. Sorry for any inconvenience caused. "
strDelay = 300    'Delay given in seconds; change this value to your preference, or set it to 0 to give no delay at all

'Open a text file of computer names
'with one computer name per line
Set oTS = oFS.OpenTextFile("C:\computers.txt")

'go through the text file
Do Until oTS.AtEndOfStream
 'get the next computer name
 'store it in variable strCompname
strCompname = oTS.ReadLine
        WshShell.Run "C:\Windows\System32\shutdown.exe -m \\" & strCompname & " -r -c " & Chr(34) & strWarning & Chr(34) & " -t " & strDelay    'Replace the "-r" switch with "-s" to make the computers shutdown instead
Loop
'close the text file
oTS.Close