Hi,I'm trying to install Microsoft Exchange 2007 SP2 on a Windows 2003 R2 x64 SP2 Standard Edition, I have .NET2.0, Powershell1.0, Windows Installer4.5, MMC3.0 all installed as indicated by the Exchage Installer first page. But I still hit by this same error, see below for the error message:1. When running setup.com /prepareschema, it show:Welcome to Microsoft Exchange Server 2007 Unattended Setup Preparing Exchange Setup Unhandled Exception: System.TypeLoadException: Method 'ReportWarning' in type 'Microsoft.Exchange.Setup.ExSetup.ExSetup' from assembly 'ExSetup, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' does not have an implementation. Exchange Server setup encountered an error.2. When running setup.exe, it show:"ExSetupUI.exe has encountered a problem and needs to close. We are sorry for incovenience."then show another windows, "Exchange Server setup encountered an error."Appreciate for help, thanks in advance.

Can you post the error entries that is there in set up log. Dont paste the whole log, just the lines with error and failed entries.Raj

Hi, this error is generated even before the setup log being generated. I've look into C:, there's no ExchangeSetupLog

Looks like version mismatch some where on .net. Can you reconfirm if that has been installed properly.Raj

I have .net 3.5 SP1 installed previously, i also have tried to reinstall it with .net 2.0, it's still the same error.

I encountered the same error but in my case, it was with Exchange 2010. Turned out to be .net related. Decided to start from scratch and install all Windows updates then run the Exchange setup. Problem went away. Hope this helps