Determining Uptime in Windows

• 1). Press "Windows + R" on the keyboard to open the "Run" dialog.
  
  
• 2). Type "Cmd" into the "Open" box and press "Ok" to open the command prompt.
  
  
• 3). Type "net statistics server" into the command prompt and press "Enter."
  
  
• 4). Scroll up through the output until you reach a line that begins "Statistics since..." The time stamp after "Statistics since..." tells you the last time your computer was booted.
  
  

Determining Uptime in OS X

• 1). Open a terminal by selecting the "Terminal" application from the "Utilities" folder in "Applications."
  
  
• 2). Type "uptime" into the terminal prompt and press "Enter" to execute the command. "Uptime" will tell you how long it has been since your computer has booted.
  
  
• 3). Read the first line that "uptime" returns. The time stamp after the word "up" indicates how many hours the computer has been running without a reboot.
  
  
• 4). Type "last reboot" into the terminal prompt and press "Enter." "Last Reboot" will output a log of your computer's recent boots.
  
  
• 5). Read the output of "last reboot" to determine the last time your computer rebooted.