Rem PowerShell Commands to Get-User Info
Get-ADUser -Filter * -Property * | Format-Table Name,SamAccountName,passwordlastset,lastlogondate -wrap

Get-ADUser -Filter {Enabled -eq $true} -Properties Name,SamAccountName,LastLogon | Select-Object Name,SamAccountName,@{n='LastLogon';e={[DateTime]::FromFileTime($_.LastLogon)}}

Rem PowerShell Command to Get-Computer Info
Get-ADComputer -Filter * -Property * | Format-Table Name,OperatingSystem,OperatingSystemServicePack,OperatingSystemVersion,lastlogondate -Wrap

Rem Save the output to a txt file using > then use excel to sort the content save back to a text text file with one computer name per line then run the following to delete old objects:
Get-Content -Path C:\ComputerList.txt | Remove-ADComputer -WhatIf

Rem If leaf objects exist run the following 

Get-Content -Path C:\ComputerList.txt | Remove-ADObject -Recursive -WhatIf

Rem remove -Whatif when ready to actually delete conntent

Rem To Automatically delete computers older than 365 days

Search-ADAccount -AccountInactive -TimeSpan 365.00:00:00 -ComputersOnly | Remove-ADObject -Recursive -WhatIf

Rem remove -Whatif when ready to actually delete conntent

Search-ADAccount -AccountInactive -TimeSpan 365.00:00:00 -ComputersOnly | select-object -Property name,LastLogonDate,DistinguishedName | out-file c:\oldcomputers.txt

Rem To Automatically users that have not logged on for 365 days, and have logged onto the system

Search-ADAccount -AccountInactive -TimeSpan 365.00:00:00 -UsersOnly | where {$_.LastLogonDate -ne $NULL} | Remove-ADObject -Recursive -WhatIf

Rem remove -Whatif when ready to actually delete conntent

Search-ADAccount -AccountInactive -TimeSpan 365.00:00:00 -UsersOnly | select-object -Property name,LastLogonDate,LastLogonTimeStamp,DistinguishedName | out-file c:\oldusers.txt

Find Users that have never logged in:
get-aduser -f {-not ( lastlogontimestamp -like "*") -and (enabled -eq $true)}

Search-ADAccount -AccountInactive -DateTime ((get-date).adddays(-365)) -UsersOnly

Find users that have not changed their password in 365 days
$d = [DateTime]::Today.AddDays(-365)
Get-ADUser -Filter '(PasswordLastSet -lt $d) -or (LastLogonTimestamp -lt $d)' -Properties PasswordLastSet,LastLogonTimestamp | ft Name,PasswordLastSet,@{N="LastLogonTimestamp";E={[datetime]::FromFileTime($_.LastLogonTimestamp)}}