There are several times when you may have installed and uninstalled a software and clicked Ok on the final screen without reading the dialog box, which in turned invoked a windows restart. Such things are really annoying and the only way to abort a shutdown currently is to quickly open the run dialog, with the shortcut key Windows + R and typing shutdown /a. Though this aborts the shutdown, it does not always work.
Shut It on the other hand is a very useful utility that will monitor your system for shutdown signals and show you a dialog box which will allow you to abort the shutdown or continue with it. You can also use it to only monitor shutdown events if certain applications or processes are running on the system. For example you may want to stop shutdowns when your download application is running or you are logged into a remote session.
To start monitoring shutdown events with Shut It, right click on the tray icon and select Properties, in the window that opens up click on shutdown checks, you can ignore the initial shutdown checks if you do not want to monitor shutdown only if certain applications or processes are selected.
Jump to the If No Shutdown Checks are detected and select the action you would like to fire incase the system is schedule to shutdown or restart.
Based on your choice appropriate actions will be taken. You can also schedule shutdown at a given interval using the built in tool, right click on the tray icon and click on Start Schedules Shutdown options, this should open a new dialog box which will give you the option to schedule a shutdown in the future.
You can easily abort the scheduled shutdowns by right click the tray icon and selecting Abort Scheduled Shutdowns. Shut It is a freeware and will only work with Windows 2000 and Windows XP and does not support Windows Vista as of now.