Event Viewer logs a ton of different things that your computer's recently done. In
order to find out when it last time it was active just follow the following procedures:
- Go to the Start menu and type "Event Viewer" in the search box. Hit Enter when its option comes up in the menu.
- Double click on Windows Logs in the left sidebar, then click on System.
- Right click on System and choose Filter Current Log.
- In the window that pops up, look for the Event Sources drop down. Choose Power-Troubleshooter from this drop-down and hit OK.
- Look at the middle pane of the Event Viewer window. At the top, you should see all the applicable recent events, in descending order of time. Anticipate the time you suspect your computer was used, and see if there are any events. If there are, you can click on them to see more details, like what woke up your computer, in the bottom middle pane.
