Article ID: 2266458 - View products that this article applies to.
Consider the following scenario:
The following error was generated when "$error.Clear(); uninstall-MsiPackage -PackagePath ($RoleInstallPath + "Mailbox\MSFTE.MSI") -Log
File ($RoleSetupLoggingPath + "\InstallSearch.msilog")" was run: "Couldn't open package 'C: \Program Files\Microsoft\Exchange Server\V14\Mail
box\MSFTE.MSI'. Another version of this product is already installed. Installation of this version cannot continue. To configure or remove the existing version of this product, use Add/Remove Programs on the Control Panel. Error code is 1638.".
The Exchange Server setup operation did not complete. Visit http://support.microsoft.com
(http://support.microsoft.com/)and enter the Error ID to find more information.
Exchange Server setup encountered an error.
The issue occurs because Update Rollup 2 for Exchange Server 2010 replaces the Msfte.msi file of the RTM version of Exchange Server 2010. Therefore, the uninstallation program cannot find the RTM version of the Msfte.msi file when it tries to uninstall Exchange Server 2010.
To resolve this issue, install the following update rollup:
(http://support.microsoft.com/kb/2407113/ )Description of Update Rollup 5 for Microsoft Exchange Server 2010 Release to Manufacturing
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.