To upgrade vCenter Server on a Windows virtual machine or physical server, your system must meet specific hardware and software requirements.
  • Synchronize the clocks on all machines running the vCenter Server 5.x services. See Synchronizing Clocks on the vSphere Network.

  • Verify that the system network name of the machines running vCenter Server 5.x services are valid, and are reachable from other machines in the network.

  • Verify that the host name of the virtual machine or physical server that you are installing or upgrading vCenter Server on complies with RFC 1123 guidelines.

  • If your vCenter Server service is running in a user account other than the Local System account, verify that the user account in which the vCenter Server service is running has the following permissions:

    • Member of the Administrators group

    • Log on as a service

    • Act as part of the operating system (if the user is a domain user)

  • Verify that the LOCAL SERVICE account has read permission on the folder in which vCenter Server is installed and on the HKLM registry.

  • Verify that the connection between the virtual machine or physical server and the domain controller is working.