The method used to check the uptime for your Windows computer is the use of CMD show uptime techniques. Open the command prompt and type systeminfo | find "System Boot Time". This will give you the date and time at which your Windows computer was booted up. Using these two data points, one can calculate the uptime of the system. An alternative technique would be the use of net stats workstation command in order to look for the "Statistics since" line. However, depending on the type of Windows computer you have and the settings therein, the command you use could return the uptime of the last boot up.