Installation Error Installing Exchange 2013 CU3 on Server 2012

Question

Hello,
When Installing Exchange 2013 on server 2012 I get the following error during Step 1 of 8 of Transport Service. I have installed and unistalled Exchange a few times, restarted the machine manually and removed exchange from AD, etc. to no avail.
Any suggestions will be very much appreciated.
Thank You.
VK
Error:
The following error was generated when "$error.Clear();
          install-MsiPackage `
          -PackagePath ($RoleInstallPath + "TransportRoles\agents\Hygiene\ASDat.MSI") `
          -LogFile ($RoleSetupLoggingPath + "\InstallASDat.msilog") `
          -PropertyValues ("ALLUSERS=1") `
          -UpdatesDir $RoleUpdatesDir
        " was run: "Installing product C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\agents\Hygiene\ASDat.MSI failed. This action is only valid for products that are currently installed. Error
code is 1605.".

Answer 1

Martina,
Thank you for your response. KB says that Machinepolicy and Userpolicy are to be set to Undefined and that is what I have.
Windows PowerShell
Copyright (C) 2013 Microsoft Corporation. All rights reserved.
PS C:\Users\Administrator> get-executionpolicy –list
Scope                                            
ExecutionPolicy
MachinePolicy                                                  
Undefined
UserPolicy                                                  
Undefined
Process                                                  
Undefined
CurrentUser                                                  
Undefined
LocalMachine                                               
RemoteSigned
VK