You have two choices for moving your vCenter Server deployment on Windows to version 6.5: you can use the upgrade on Windows process or you can use the migration process to convert your deployment to an appliance at the same time that you upgrade the deployment to version 6.5.

It is important to understand the differences and similarities between upgrading and migrating vCenter Server instances on Windows.

Choose the upgrade on Windows process to upgrade a vCenter Server version 5.5 or version 6.0 deployment on Windows to a vCenter Server 6.5 deployment on Windows. For details, see Upgrading vCenter Server for Windows.

Choose the migration to an appliance process to convert a vCenter Server version 5.5 or version 6.0 deployment on Windows to a vCenter Server Appliance 6.5 deployment. For details, see Migrating vCenter Server for Windows to vCenter Server Appliance.

You can migrate the following vCenter Server deployment types from Windows to appliances while upgrading to version 6.5:

vCenter Server with an embedded vCenter Single Sign-On (version 5.5) or Platform Services Controller (version 6.0)

vCenter Server with an external vCenter Single Sign-On (version 5.5) or Platform Services Controller (version 6.0)

You can migrate with an embedded or external vCenter database. In either case, the database is converted to an embedded PostgreSQL database on the new appliance. For more about the database migration, see Preparing vCenter Server Databases for Migration.

You can migrate a vCenter Server installation to an appliance using either the GUI method or CLI method.

When migrating vCenter Server with an embedded vCenter Single Sign-On (version 5.5) or Platform Services Controller (version 6.0), the migration is a single workflow.

When migrating vCenter Server with an external vCenter Single Sign-On (version 5.5) or Platform Services Controller (version 6.0), migration order matters. You migrate vCenter Single Sign-On (version 5.5) instances or Platform Services Controller instances before migrating vCenter Server instances. For details, see Migrating vCenter Server for Windows to vCenter Server Appliance.

Preparation includes using VMware Migration Assistant to gather the required information on the source vCenter Server instance, vCenter Single Sign-On instance, or Platform Services Controller instance. For details, see Download and Run VMware Migration Assistant on the Source Windows Machine.