Say it's midnight and you want to call it a day. But the issue is that you are downloading some huge files from the Internet via Firefox (see screenshot) and at your current internet speed, the download will take another two hours to finish.

You could either cancel the downloads, or leave the computer in running state (forget environment), or just install Auto Shutdown from mozilla.org.
As the name suggest, this extension will turn off the computer automatically as soon as Firefox has downloaded all the pending files in the queue.
If you not using Firefox, try the shutdown command in Windows that will turn off the computer after the given time. For instance, if you want to turn off the computer in next two hours, type the following in Windows Run box:
shutdown -s -t 7200 [7200 = 2 hours]
The Auto Shutdown extension of Firefox internally executes the same command.
Related: Shut Down Your Computer Quickly
Find this article at: http://labnol.blogspot.com/2007/09/let-firefox-turn-off-computer-when-all.html
web: http://www.labnol.org/ email: amit@labnol.org

Reader Comments
Unluckily, this add-on do not work for Mac. Should'nt that be a more easier way to do it for the Mac?
Written on 14/9/07 12:36 PM
True because Auto shutdown is internally using the Windows command - shutdown.exe - which is not available for the Mac.
Written on 14/9/07 1:27 PM
I use a utility called DShutdown for shutingdown my PC. Its a whole configurable and cane be used to shutdown and wake up local or remote PCs
Written on 14/9/07 6:38 PM