If you want to know how long your Windows computer has been running, you can easily find your System Uptime. Uptime is a term used for referring to the time your computer has been running continuously without a reboot. This post will show you how to find System Uptime in Windows 10 / 8.1 / 7 / Server, using CMD, SystemInfo command, PowerShell, Task Manager.
Find Windows System Uptime
1] Using PowerShellOpen an elevated PowerShell prompt, type the following and hit Enter:
(get-date) - (gcim Win32_OperatingSystem).LastBootUpTime

You will see the Boot up times in days, hours, minutes, seconds and milliseconds.
Here, you are using the Get-Date cmdlet to return the current date and time, and then subtracting the value of the LastBootUpTime property that comes from the Win32_OperatingSystem, says TechNet. GCIM is an alias for Get-CimInstance.
2] Using CMDIf you want to find out the Server Statistics, you can open an elevated CMD type the following and hit Enter:
net stats srv
The first line ‘
Statistics since‘ will show you the Windows uptime.
3] Using Task ManagerIf you open Task Manager, under the Performance tab, you will see your computer Up time displayed there.
4] Using SystemInfo toolThe built-in SystemInfo tool lets you view the System Boot Time. It displays the date and time at which the computer booted.
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