Finding out when you last rebooted your Windows 7 machine can be completed using the “systeminfo” command.
Open a Command Prompt by going to Start and opening “cmd”. You will then be presented with a command prompt window, where you need to type the systeminfo command below:
C:\> systeminfo | find "System Boot Time" System Boot Time: 05/06/2010, 12:55:07
You will then be shown the date and time the server was booted (as seen in the example above).
You can just run “systeminfo” on it’s own (with no ‘| find “System Boot Time”‘), and you will be presented with a lot of other information such as Hotfixes, Network Connections, etc.