Before proceeding, here are some  prerequisites:

1. Windows server version: Ensure you're working on a domain controller running Windows Server 2012 R2 with Active Directory.

2. Domain Controller Accessibility: All devices that the policy applies to must have network access to a Domain Controller. The GPO settings are propagated from the Domain Controller to the end devices.

3. Appropriate Permissions: The individual or team implementing the GPO should have appropriate permissions. Typically, this means being a member of the "Group Policy Creator Owners" group or having similar rights.

4. BitLocker Requirements: If you are forcing BitLocker encryption via GPO:

5. TPM version: Ensure devices have a Trusted Platform Module (TPM) chip, version 1.2 or higher. BitLocker uses this for encryption. While BitLocker can function without TPM, using TPM provides additional security.

6. Partitions: The hard drive should have at least two partitions: a system partition, which includes the necessary files to start the system, and an operating system partition.

7. File System Compatibility: BitLocker can encrypt only drives formatted using the NTFS, FAT16, FAT32, or exFAT file systems.

8. Backup Strategy: Before encrypting any drives, have a comprehensive backup strategy in place. In the event something goes wrong, or a password is forgotten, you don't want to risk data loss.

9. Understanding of Recovery Protocols: Before deploying BitLocker, ensure that you and your team understand the recovery process. In scenarios where users forget their BitLocker password or if there are issues with TPM, you'll need to use recovery keys to access the data.

10. BitLocker Network Unlock (Optional): If devices in your organization utilize the network unlock feature, ensure the necessary infrastructure is in place. This feature allows BitLocker-encrypted computers connected to the corporate network to boot automatically without requiring user input.

 Creating the GPO for USB Drive Encryption:

1. Initiate Group Policy Management:

• Click on the Start menu.

• Locate and open the Group Policy Management tool.

2. Navigate to Group Policy Objects:

• Once inside Group Policy Management, find the folder named Group Policy Objects.

3. Create a New Policy:

• Right-click the Group Policy Objects folder.

• Select New.

• Name your new policy. In this example, we'll use "FORCE USB ENCRYPTION".

4. Editing the New GPO:

• Expand the Group Policy Objects folder.

• Right-click on your new GPO (FORCE USB ENCRYPTION) and select Edit.

5. Configuring Bitlocker Settings:

• Inside the group policy editor, navigate to: Computer Configuration > Administrative Templates > Windows Components > Bitlocker Drive Encryption > Removable Data Drives.

• Open the Removable data drives folder.

• To disable write access to unencrypted USB storage devices, double-click on Deny write access to removable drives not protected by Bitlocker and select Enable.

• If you wish to enable Bitlocker compatibility for earlier Windows versions, double-click on Allow Access to BitLocker Protected Removable Drives From Earlier Versions of Windows and select Enable.

• After setting configurations, close the group policy editor. The configurations will be saved upon closing.

Things to consider while creating the GPO for USB drive encryption:

1. Advanced Security Filtering:

While setting up your GPO, you can utilize security filtering to apply the policy to specific users, groups, or devices, giving you granular control.

• In the Group Policy Management Console, select your GPO.

• Under the Scope tab, in the Security Filtering section, remove the default Authenticated Users group.

• Click on Add and select the specific groups or users you want the policy applied to.

2. GPO Status Configuration:

To optimize performance and avoid unintended settings application, you can disable the user or computer configuration settings of a GPO if they are not used.

• Right-click your GPO and select GPO Status.

• Choose User configuration settings disabled or Computer configuration settings disabled as appropriate.

3. Setting Up GPO Comments:

For better documentation and clarity, especially in larger organizations, always add comments to your GPOs.

• Right-click on your GPO, choose Edit, and navigate to Properties.

• Head to the Comment tab and jot down important notes or the purpose of the GPO.

Applying the GPO for USB Drive Encryption:

1. Linking the GPO:

• Return to the Group Policy Management screen.

• Right-click the Organizational Unit (OU) where you wish to apply the policy and select Link an existing GPO.

• Link to the "FORCE USB ENCRYPTION" policy. For demonstration purposes, we're linking it to the root of a domain named "TECH.LOCAL".

2. Wait and Replicate:

• After applying the GPO, allow 10-20 minutes for the policy to replicate across other domain controllers in your network.

3. Reboot and Test:

• Reboot a user's computer. Upon boot-up, the computer will retrieve and apply the new group policy.

• Connect a USB storage drive to the computer and attempt to save a file.

• If the USB is unencrypted, the computer should deny write access and prompt for encryption via Bitlocker.

• After encrypting with Bitlocker, data writing should be permitted.

Things to consider while applying the GPO for USB drive encryption:

1. GPO Inheritance and Precedence:

Remember, in a domain, multiple GPOs can be linked to an Organizational Unit (OU). It's crucial to understand how GPOs are inherited and which GPO has precedence.

• You can view the inheritance tab in the Group Policy Management Console for an OU to see the order of precedence. If there's a conflict, the GPO at the top will have the highest priority.

2. Using WMI Filters for Targeting:

Create WMI (Windows Management Instrumentation) filters to target the GPO to specific OS versions or system characteristics.

• In the Group Policy Management Console, right-click WMI Filters and select New.

• Define your queries. For example, to target only Windows 10 machines, your query would be: SELECT * FROM Win32_OperatingSystem WHERE Version LIKE "10%" AND ProductType = "1"

3. GPO Update Frequency:

By default, GPOs refresh every 90 minutes, with a random offset of 0 to 30 minutes. However, in urgent situations, you don't need to wait.

• Force a manual GPO update using the gpupdate /force command on the target machines.

4. Testing GPO Application:

Before deploying a new GPO organization-wide, always apply it to a test OU with few devices. This helps to ensure there are no unexpected outcomes or conflicts.

• Once tested, gradually rollout to the entire organization, monitoring for any issues.

Advanced Configuration Options:

1. Recovery Options:

To ensure data is always accessible, even if users forget their password or if the USB drive malfunctions, set up Bitlocker recovery options.

• Navigate to: Computer Configuration > Administrative Templates > Windows Components > Bitlocker Drive Encryption > Removable Data Drives.

• Enable Choose how Bitlocker-protected removable drives can be recovered. This will allow admins to access recovery passwords and use data recovery agents.

2. Password Policy:

Strengthen encryption by setting robust password policies for Bitlocker.

• Inside Removable Data Drives, select Set password complexity for Bitlocker and configure as desired. It's recommended to set a policy that mandates the use of uppercase, lowercase, numerical, and special characters.

3. Silent Encryption:

To enhance user experience, enable silent encryption where users are not constantly prompted during the encryption process.

• Go to Configure use of hardware-based encryption for removable data drives and enable it.

Best Practices for Managing GPOs:

1. Backup Your GPOs:

Regularly back up your GPOs to safeguard against accidental changes or deletions.

• In the Group Policy Management Console, right-click the desired GPO and select Back Up.

2. Use Descriptive Names:

Naming GPOs descriptively helps in easier management and understanding.

For instance, "USB_Encryption_2023_Q4" is more descriptive than just "USB_Encryption".

3. Implement Advanced Auditing:

Keep track of who's doing what with your GPOs. Enable advanced auditing to get detailed logs.

• Navigate to: Computer Configuration > Policies > Windows Settings > Security Settings > Advanced Audit Policy Configuration.

Monitoring and Maintenance:

1. Regularly Review and Update Policies:

• Security requirements can change. Regularly review and update your GPOs to match current security standards and organizational needs.
  

2. Monitor Policy Application:

• Use tools like Resultant Set of Policy (RSoP) or gpresult command to verify that policies are applied correctly to user machines.
  

3. Test Before Applying:

• Always test new policies on a subset of devices before rolling them out network-wide to avoid potential disruptions.

Check out here to know about How to Control USB Access on select Devices using GPO

Conclusion:

A multi-layered approach to security, incorporating both basic and advanced GPO configurations, ensures that your organization's data remains shielded against threats. By continually updating, monitoring, and refining your policies, you ensure that your network's defenses remain robust and resilient in the face of evolving challenges.