Prevent your computer from being shut down or re-started
Sometimes, it is necessary that computer will be remain not closed under any conditions!
To example:
When you are running web server on your computer.
When you are doing defragmentation of your hard disks.
When you are connected to the Internet, hackers can reboot or shut down your computer, using programs such as NetBus or Back Orifice. More than 300 such programs exist in our time!!!
If you are installing new program that requires rebooting but you don't want to reboot computer click OK to this installation program, but your computer will not be rebooted! (This is very useful if you are running web server on your computer)