Upgrade options for vCenter Server on Windows depend on your existing deployment type and version.

You can upgrade the following deployments:

Table 1. Supported vSphere Upgrade Paths
Before Upgrade After Upgrade
vCenter Server 5.5 with an embedded vCenter Single Sign-On on Windows vCenter Server 6.5 with an embedded Platform Services Controller on Windows
vCenter Server 6.0 with an embedded Platform Services Controller instance on Windows
vCenter Single Sign-On 5.5 on Windows Platform Services Controller 6.5 on Windows
Platform Services Controller 6.0 on Windows
vCenter Server 5.5 on Windows vCenter Server 6.5 on Windows
vCenter Server 6.0 on Windows

For upgrade steps for a vCenter Server 5.5 deployment, see Upgrading vCenter Server 5.5 on Windows. For upgrade steps for a vCenter Server 5.5 deployment, see Upgrading vCenter Server 6.0 on Windows.

Important: You cannot change your deployment type during upgrade.
You cannot uninstall or reinstall individual services during the upgrade process. For example, vSphere Auto Deploy can no longer be deployed separately as it was in vCenter Server 5.5. It is part of the vCenter Server group of services for vCenter Server 6.5. For details on upgrading from 5.5 with distributed services, see Distributed vCenter Server 5.5 for Windows Services Relocation During Upgrade or Migration.
Note: Starting with vSphere 6.5, the vCenter Server services are not standalone services under Windows SCM, instead they run as child processes of the VMware Service Lifecycle Manager service.