CU6 Update failing prerequisite check WinMgmt "Access is denied."

I'm attempting to upgrade Exchange 2013 and am seeing the following error message. I've been unable to get past it and haven't found any helpful information in my research on what to do. Thoughts?

Welcome to Microsoft Exchange Server 2013 Unattended Setup
Languages
Mailbox role: Transport service
Client Access role: Front End Transport service
Mailbox role: Client Access service
Mailbox role: Unified Messaging service
Mailbox role: Mailbox service
Management tools
Client Access role: Client Access Front End service

Performing Microsoft Exchange Server Prerequisite Check

    Configuring Prerequisites                                                                         FAILED
     The following error was generated when "$error.Clear();
          if (Get-Service WinMgmt* | ?{$_.Name -eq 'WinMgmt'})
          {
            Set-Service WinMgmt -StartupType Automatic
            Start-SetupService -ServiceName WinMgmt
          }
        " was run: "Service 'Windows Management Instrumentation (WinMgmt)' cannot be configured due to the following err
or: Access is denied".

    Prerequisite Analysis                                                                             COMPLETED

The Exchange Server setup operation didn't complete. More details can be found in ExchangeSetup.log located in the
<SystemDrive>:\ExchangeSetupLogs folder.