Here is a powershell script that can be used to cleanup old computer AD accounts:
Import-Module ActiveDirectory
$date = get-date
$systems = Search-ADAccount -ComputersOnly -AccountInactive -TimeSpan 365
foreach($computer in $systems){
$computer | select-object Name, OperatingSystem, DistinguishedName, LastLogonTimeStamp >> “C:\Scheduled Tasks\AD Cleanup\SystemInfo.csv”
$computer | disable-adaccount
$computer | move-adobject -targetpath “ou=Dormant Computers,dc=xxxx,dc=xxx”
write-host “$computer will be moved to Dormant computers”
}
First we load the Active Directory Module into Powershell. This has to be added as a Winodws Feature first.
Then we search the AD for all computer accounts which have been inactive for the last 365 days.
In the foreach loop we write the name of the server and LastLogonDate to a csv file to keep as a log.
Then we disable the account and move it to a OU where we keept disabled accounts.
Last we output a stsus message to the console.
Staffan Olofsson
B3IT on Microsoft 
Do not use this, it started disabling and moving all of my computers, not just inactive ones. Find a different script that gives you the list of what it will do first.
Hello. I would start by saying that you should of course not run any scripts from the net before testing and understanding the functionallity fully. Commenting out the two rows that disables and actually moves the account’s would have been a good approach. In this case there was actually a typo in the script that affected results set. The third row should look like this;
$systems = Search-ADAccount -ComputersOnly -AccountInactive -TimeSpan 365
Excellent, this is very helpful to disable unused computer active directory account but I found automate active directory clean from http://activedirectorycleanup.hatenablog.com/ to identify inactive or old computer accounts that have been inactive for 180 days. It helps to clean inactive computer accounts and view report means what actions have been taken for inactive accounts.
Thanks, glad it was useful.