Uptime Gadget

Uptime Gadget is a very small desktop gadget that shows time since the last computer shutdown. It is very easy to install and set up.
The tool does not comprise any special settings, so it can be used with confidence even by people with no experience with computer software.
The interface is made of a very small frame that you can move to any position on the screen using the mouse cursor.
Thanks to built-in Windows features, you can set the window to stay on top of other apps, as well as change its opacity level by choosing a preset value ranging between 20% and 100%. It is non-intrusive, enabling you to work in other applications at the same time without a problem.
Uptime Gadget shows the current uptime expressed in number of days, hours, minutes and seconds. As you have probably suspected, it shows data in real-time mode. The app does not include any options of its own.
Since this is a Windows gadget, Uptime Gadget runs on a very small amount of CPU and RAM, which means that it does not affect the computer's overall performance. It did not cause the operating system to hang, crash or pop up error dialogs during our evaluation.
In conclusion, Uptime Gadget comes in handy whenever you want to know your computer's uptime, especially when leaving it turned on and unattended, in order to identify automatic restarts (e.g. Windows updates) or find out if someone else has been tinkering with power options.