Check If Your computer was used in your absence? Do you want to know whether your PC was used in your absence? Just follow these simple steps: => Goto Run and type eventvwr.msc in the Run dialog box. => Events are stored in three log files: Application,Security, and System. These logs can be reviewed and archived. => For our purposes we want the System log. Click on “System” in the left-hand column for a list of events. => Look for a date and time when you weren't home and your computer should have been off. => You can also use this log to see how long someone was on the computer. => Just look at the time the computer was turned on and off for that day.