When you want to work in the late hours without getting sleepy, you drink coffee. The caffeine inside the coffee (or tea) keeps you awake, alert and prevents you from sleeping. How about you give a little bit of caffeine to your computer too, to prevent it from dozing off. Yes, a freeware program called Caffeine can prevent your PC from sleeping, shutting down or hibernating. It keeps PC awake by generating random keypress events, making Windows think that your PC is not idle.
You can download Caffeine from the Zhorn software website. The download is available as a portable application. The download is very small in file size. You can just extract the contents of the downloaded ZIP file and run caffeine.exe from there. The application does not have any window interface. It just sits in the notification area and keeps your PC awake.
You can right-click on the notification area icon and toggle the active mode for Caffeine. In the active state it keeps your PC awake, while in the inactive mode it stops working and allows your PC to be idle. You can also set a timer for it be active or inactive. You can choose that it should stay active for 1 hour, 2 hours, 4 hours, 8 hours or 24 hours. Similarly, you can choose a time period for it to stay inactive.
If you want more from this little app, then you can launch it from command line by specifying some command line parameters. For example, launching with -noicon parameter hides the icon in the system tray. You can see a complete list of command line options in the About dialog of Caffeine which you can open from the right-click menu of the notification area icon.
By default, Caffeine simulates the pressing of the F15 key on your computer every 59 seconds in order to keep it awake. The simulation of the key press event makes your machine think that you are still working at the keyboard, so it does not lock the screen or activate the screen-saver. In the command line options, you can change the key press to be any other key of your choice.
You can download Caffeine from http://www.zhornsoftware.co.uk/caffeine/.