Your Select-Object does not get any input ...
This should work actually:
$domain = "consto.com"
$DaysInactive = -30
$time = (Get-Date).Adddays($DaysInactive)
$OUs = "OU=Servers,OU=location1,DC=consto,DC=com","OU=Servers,OU=location2,DC=consto,DC=com"
$Result = ForEach($OU in $OUs){
Get-ADComputer -Filter "LastLogonTimeStamp -lt $time" -Properties LastLogonTimeStamp -SearchBase $OU |
Select-Object -Property Name,@{Name="Stamp";Expression={[DateTime]::FromFileTime($_.lastLogonTimestamp)}}
}
$Result
$Result | Export-Csv -Path G:\ISO\OLD_Computer.csv -NoTypeInformation
Best regards,
(79,108,97,102|%{[char]$_})-join''