This is actually a VERY simple script.  But if you're new to Powershell and work with Active Directory you'll appreciate it.

Searches a specific OU in Active Directory for Accounts that have not logged in for 90 days.  You can edit the number of days to be more restrictive.  The present script just "lists"

If you comment out the line that says "GET-QADUSER" but putting a # before it and UNCOMMENT the last line it will autoDisable (NOT DELETE) those accounts