win/stay_awake.ps1

   1 $wsh = New-Object -ComObject WScript.Shell
   2 $minutes = 15
   3 do{
   4         "Staying awake for $minutes minutes"
   5   $minutes-=1;
   6   # Send Shift+F15
   7   $wsh.SendKeys('+{F15}')
   8   Start-Sleep -seconds 59
   9 }until($minutes -lt 0)
  10 # Thank you to http://www.zhornsoftware.co.uk/caffeine/