DC Server OS:Windows Server 2008 (Hyper-v guest OS)1024 mb ram Mail Server OS:Windows Server 2008 (Hyper-v guest OS)4096 mb ram Isure source is x64 Exchange Server 2007 SP1 download in Microsoft site (SW_DVD9_NTRL_Exchange_Svr_Ent_2007w_SP1_X64_English_STD_ENT_X13-93829) thanks install log: [8/4/2008 7:33:35 PM] [1] Processing component 'Transport Common Configuration' (Configuring common transport properties).[8/4/2008 7:33:35 PM] [1] Executing 'register-ContentFilter', handleError = False[8/4/2008 7:33:35 PM] [2] Launching sub-task '$error.Clear(); register-ContentFilter'.[8/4/2008 7:33:35 PM] [2] Beginning processing.[8/4/2008 7:33:35 PM] [2] [ERROR] Failed to register the content filter.[8/4/2008 7:33:35 PM] [2] [ERROR] This version of %1 is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need a x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher[8/4/2008 7:33:36 PM] [1] The following 1 error(s) occurred during task execution:[8/4/2008 7:33:36 PM] [1] 0. ErrorRecord: Failed to register the content filter.[8/4/2008 7:33:36 PM] [1] 0. ErrorRecord: Microsoft.Exchange.Data.Common.LocalizedException: Failed to register the content filter. ---> System.ComponentModel.Win32Exception: This version of %1 is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need a x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher at System.Diagnostics.Process.StartWithShellExecuteEx(ProcessStartInfo startInfo) at Microsoft.Exchange.Management.SystemConfigurationTasks.ContentFilterRegistration.InternalProcessRecord() --- End of inner exception stack trace ---[8/4/2008 7:33:36 PM] [1] [ERROR] Failed to register the content filter.[8/4/2008 7:33:36 PM] [1] [ERROR] This version of %1 is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need a x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher[8/4/2008 7:33:36 PM] [1] Setup is halting task execution because of one or more errors in a critical task.[8/4/2008 7:33:36 PM] [1] Finished executing component tasks.[8/4/2008 7:33:36 PM] [1] Ending processing.

Its time to try alternate source of setup or download it from here Download details: Exchange Server 2007 Service Pack 1

Clarify: unable to install HUB Transport Role [ERROR] This version of %1 is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need a x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher Amits right. DoNetUser, are you sure its x64 Windows Server 2008?

Hi, DoNetUser, I assume your question has been answered, and I'd like to change the status to "Marked as answer", please feel free to post here if you have any update

Isure its x64 Windows Server 2008

I try thissource.Install is right. thanks. Download details: Exchange Server 2007 Service Pack 1