Richard Siddaway's Blog

A question came up on the forum regarding when Windows Update last run and when an update was last installed.  Get-Hotfix shows the date of installation for most BUT not all patches.

The registry holds values showing last successful detection and install:

$props = [ordered]@{
LastDetect = Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\Results\Detect' -Name LastSuccessTime |
select -ExpandProperty LastSuccessTime

LastInstall = Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\Results\Install' -Name LastSuccessTime |
select -ExpandProperty LastSuccessTime
}

New-Object -TypeName psobject -Property $props