You can easily check your Windows start up time history. Windows operating system always maintains a history. To get the history go through the steps:
- Go to C:\Windows\Tasks and find the SCHEDLGU.TXT. (If your windows is installed in another drive except c:, go to the particular drive where the windows is installed and go :\Windows\Tasks.)
- Open the file and you can check the history like Started at 1/02/2013 9:53:46 PM.
Try it yourself.