Caffe1ne

Caffe1ne is a tiny and portable application which prevents your computer from locking, hibernating or activating the screensaver. It can be easily figured out, even by less experienced users.
Since installation is not necessary, you can store Caffe1ne on a USB flash drive or any other removable device, save it to any computer, and directly run its executable file.
What's more important is the fact that the Windows Registry does not receive new entries, and no leftover files can be found on the hard drive after deleting the tool. Plus, you can always have Caffe1ne with you whenever you're on the move.
Upon program initialization, Caffe1ne automatically minimizes to the system tray area. When it is enabled, the tool simulates the user pressing the 'Shift' key every 59 seconds, thus stopping the computer from entering an idle state.
This type of application can come in handy when you need to temporarily disable all these aforementioned power management functions; instead of deactivating them one at a time for a brief time interval, you can use Caffe1ne.
The straightforward software application barely uses CPU and system memory, so it is not a concern to the computer's resources. It has a good response time and didn't cause us any issues throughout our testing, such as freezing, crashing or popping up error dialogs. Thanks to its overall simplicity, first-time users may quickly learn how to work with this app. On the downside, Caffe1ne has not been updated for a very long time.