AD Tidy can clean up unused active directory accounts, it search your Active Directory domain for user / computer accounts that match your search criteria (for example all accounts in a specific OU that have not logged on for 30 days).
Then you can perform a number of actions on the accounts that were found - such as moving them to another OU, disabling them, or removing them from all groups.

AD Tidy Features:
1. Search for user or computer accounts
2. Search entire domain or select a specific OU
3. Specify alternate credentials to connect to domain with
4. Get account last logon information from all DCs or select specific DCs
5. Optionally only find accounts that have not logged on for a specified number of days
6. Exclude or include disabled accounts, or only find disabled accounts
7. Exclude specific account names from the search results
8. Save search settings to file so that you can reload them whenever you want
9. Works with domains that you are not a member of (assuming you provide valid credentials)
10. Help buttons within the application explain what each setting is for

Requirements:
* Active Directory
* NET Framework

The license of this software is Freeware, you can free download and free use this server utility software.