The vCenter Host Agent Pre-Upgrade Checker reports known issues that might prevent a successful upgrade of the vCenter Host Agent software.

For more information about the vCenter Host Agent Pre-Upgrade Checker, see About the vCenter Host Agent Pre-Upgrade Checker.


  • Verify that the ESX/ESXi hosts are managed by vCenter Server.
  • Verify that the vCenter Host Agent software is running on each managed ESX/ESXi host.
  • Verify that you have Internet connectivity from the vCenter Server system. This allows new updates to be applied to the tool and allows you to view the reports and the Knowledge Base (KB) articles associated with the reports.
  • Download the vCenter Server installer. See Download the vCenter Server Installer.


  1. In the software installer directory, double-click the autorun.exe file to start the installer.
  2. Select Host Agent Pre-Upgrade Checker and click Install.
  3. Select the DSN for the vCenter Server system you are upgrading from and select the login credentials that are appropriate for that DSN.
    If you are not sure which credential type to select, check which authentication type is configured for the DSN ( Control Panel > Administrative Tools > ODBC Data Sources > System DSN).
  4. If the DSN requires a login for the credential type in use, enter a user name and password and click Next.
  5. Select an option for scanning all hosts or specific hosts.
    Option Action
    Scan all of the hosts Select Standard Mode and click Next.
    Specify hosts to scan
    1. Select Custom Mode and click Next.
    2. Select the hosts to scan and click Next. To select all hosts in a cluster, double-click the cluster.
  6. Click Run Precheck.
    The tool takes 30-40 seconds for each host.
  7. When the check is complete, click Next.
  8. View the pre-upgrade reports.
    • To view the report for an individual host, click the link next to the host name.
    • To view a summary report for all hosts, click View Report.


You have a list of issues to resolve before you upgrade.

What to do next

From the report, use the linked KB articles to research and resolve the issues for each host. After you resolve the issues, rerun the vCenter Host Agent Pre-Upgrade Checker. Repeat this process until you resolve all the reported issues, and proceed with your upgrade.