If you are using Windows Server 2003 or 2008 then you have noticed that whenever you click on Shutdown button, it shows a dialog box asking for the reason. You have to select the option from drop-down box or write into Comment box to shutdown the system.
Many ppl find it annoying and want to remove it but they don't know the method to remove it. Here I'll tell you a simple way to completely remove this annoying dialog box:
Type gpedit.msc in RUN dialog box and press Enter.
It'll open Group Policy Editor. Now expand:
Computer Configuration -> Administrative Templates -> System
In right-side pane, look for "Display Shutdown Event Tracker" option.
Now double-click on "Display Shutdown Event Tracker" and select "Not Configured" or "Disabled". Now Apply it and the annoying dialog box will disappear.
NOTE: You can also use this method to enable Shutdown Event Tracker in Windows client OS like Windows XP, Vista, etc. Just set the option value to "Enabled".