That is actually a difficult question since you COULD have built your own log of events. However, assuming your friend was talking about a system-maintained log, there are a couple of choices. Depending on which version of WINDOWS you are using, you get to it through whatever serves as "Control Panel." You need to find the "Administrative Tools" and from there, open the "Event Viewer" - which is a complex screen. You will have a few choices no matter which version of Windows you are on, and some of them could be third-party logs created using system service calls to create and update a specific app's logs. For instance, my Kaspersky Internet Security s/w has its own log that I can view through Event Viewer (though I could also see THAT one through Kaspersky's control panel.)
I'm doing this reply from a Win7 system. When I get to the event viewer, on the left-hand side I see Windows Logs, Applications and Services Logs, and Subscriptions. The Windows Logs can be expanded to Application, Security, Setup, System, and Forwarded Events. The Applications and Services Logs can be expanded to ACEEventLog, Hardware, IE, Kaspersky, Key Management Service, Media Center, MS Office Alerts, Windows Power Shell, and a sub-folder for Windows. The sub-folder expands into a typical MS "cast of thousands"
If I were looking for specific events, I would look first under the Windows logs in Application, then System, then Security. After that, I might consider the Apps and Services logs in ACEEventLog, Hardware, and MS Office Alerts.
If no joy after any of those searches, I would begin to think that the answer wasn't in any of those.
Remember when searching that the logs record the system-clock time of each event. Therefore, if you know approximately when your event occurred, it should be easy to either find it or decide that it isn't there.
