Sometimes you set Windows to perform some time consuming task, for example, encoding a video or audio or downloading a large file. During those times, it is highly undesirable for the Windows to slip into the sleep or hibernation mode for the obvious reason. You can change the Windows settings to turn off the sleep settings completely, but a smarter way is to turn them off temporarily. The free software Sleep Preventer is a small, portable tool which can help you easily prevent your PC from sleeping, hibernating or dimming off the screen.
You can download Sleep Preventer from http://darkfame.net/. The download is a portable program compressed inside a ZIP archive. You can use a tool like freeware jZip to extract files from the ZIP archive. After extracting files to a folder, you can run the Sleep Preventer.exe by double-clicking on it.
The interface of this tiny application is very easy to use. Just select a timer value from the drop-down listbox. The default value of the timer is Infinite but you can choose any desired value from the list (5, 10 or 30 minutes, 1 or 2 hours). You can also choose to let the display sleep by checking the checkbox labeled Allow display to sleep which would allow your screen to dim off. After selecting the values, click on the Prevent Sleep button to start the prevention of sleep. This would change the clicked button into Preventing Sleep button.
Later if you want to disable the sleep prevention off, then just click on the Preventing Sleep button again. Alternatively, you can also toggle the sleep prevention on or off by right-clicking on the Sleep Preveter notification area icon and choosing Toggle On / Off as shown.
The Sleep Preventer works in all the editions of Windows 7 and Vista. It is easy to use, portable and does not require installation. It can save you from the trouble of changing the sleep and hibernation options buried deep in the Control Panel settings. So if you do not want your computer to sleep, then you can do so easily with Sleep Preventer without bothering to tinker the Windows settings through the Control Panel.