Conforme mostrado na citação abaixo, não há GPO para essa ação. Você pode usar o comando dsquery para crie um script que encontre usuários que ficaram inativos por 30 dias com o -interruptor inativo
To display the distinguished names of all users in the current domain only whose names end with "Smith" and who have been inactive for three weeks or more, type:
dsquery user domainroot -name *smith -inactive 3
Esta postagem na Technet da Microsoft lista as informações acima:
There is no in-built GPO for the same.
Alternately you can use dsquery to list users who have not login in the past 30 days and disable the account.
Use the -inactive switch http://technet.microsoft.com/en-us/library/cc725702(WS.10).aspx other good methods are using adtidy (free GUI tool) http://www.cjwdev.co.uk/Software/ADTidy/Info.html dsquery user -inactive 4 (which will list accounts inactive for 4 WEEKS) or use http://www.joeware.net/freetools/tools/oldcmp/index.htm