In PowerShell 3.0 and better, it's trivial to get back real DateTime information from WMI using Get-CimInstance. This would tell you when your system was last booted:
#requires -Version 3 (Get-CimInstance -ClassName Win32_OperatingSystem).LastBootUpTime
In PowerShell 2.0, your only choice is Get-WmiObject which reports the information in internal WMI format:
(Get-WmiObject -Class Win32_OperatingSystem).LastBootUpTime
Here, you would have to convert the WMI format manually:
$object = Get-WmiObject -Class Win32_OperatingSystem $lastboot = $object.LastBootUpTime $object.ConvertToDateTime($lastboot)
The ConvertToDateTime() conversion method is actually an attached method. Behind the scenes, it is a static method call that does the job:
$object = Get-WmiObject -Class Win32_OperatingSystem $lastboot = $object.LastBootUpTime [System.Management.ManagementDateTimeConverter]::ToDateTime($lastboot)
