Veeam Backup & Replication Install Fails with: "A later version of Veeam Explorer for Microsoft Exchange is already installed."

3. When prompted to select which components to uninstall, ensure that all are selected, and then click Remove.
4. After the Uninstall is complete, open an Administrative PowerShell console (Win+X, tap A) and run the following PowerShell command to ensure that the conflicting Veeam Explorer packages were removed:
   
   ^{Note: Getting the error "No package found for 'Veeam Explorer for Microsoft*'." is acceptable and means all conflicting packages were removed by the Veeam Backup & Replication uninstaller.}

5. Relaunch the Veeam Backup & Replication installer again, and proceed through the install process.
   
6. If prompted about the configuration database being used by a Veeam server installed on the same machine, select Yes.

7. After the installation of Veeam Backup & Replication completes, launch the Veeam Backup for Microsoft 365 installer and click the Install Veeam Explorers link in the bottom-left corner.

Prevention

Review the following scenarios and follow the respective instructions.

Neither Veeam Backup for Microsoft 365 nor Veeam Backup & Replication is currently installed.

• Install Veeam Backup & Replication first.
• Then, install Veeam Backup for Microsoft 365.
  (Review: KB4638: Deploying Veeam Backup for Microsoft 365 Using Existing Veeam Backup & Replication PostgreSQL Instance)
   

Veeam Backup for Microsoft 365 is installed, but Veeam Backup & Replication is not installed yet.

1. Open an Administrative PowerShell console (Win+X, tap A) and run the following PowerShell command to uninstall the conflicting programs before installing Veeam Backup & Replication:    

2. Install Veeam Backup & Replication.
3. After the installation of Veeam Backup & Replication completes, launch the Veeam Backup for Microsoft 365 installer and click the Install Veeam Explorers link in the bottom-left corner.