Question

How can I detect if a user has logged on or off from a windows system (preferably that works with win7, vista or XP) using powershell?

I want to register the date and time of each logging on and off of the machine.

Thank you in advance

Answer 1

You can get this infromation from the event log:

Get-EventLog System -Source Microsoft-Windows-Winlogon

Logons have an InstanceId of 7001, logoffs have 7002. The user account is a SID in ReplacementStrings.

Here is some more useful code for you.

$UserProperty = @{n="User";e={(New-Object System.Security.Principal.SecurityIdentifier $_.ReplacementStrings[1]).Translate([System.Security.Principal.NTAccount])}}
$TypeProperty = @{n="Action";e={if($_.EventID -eq 7001) {"Logon"} else {"Logoff"}}}
$TimeProeprty = @{n="Time";e={$_.TimeGenerated}}
Get-EventLog System -Source Microsoft-Windows-Winlogon | select $UserProperty,$TypeProperty,$TimeProeprty

You can also get these events from a remote computer by adding the “-ComputerName” parameter to Get-EventLog.