Hey, i planned an installation Ex.2K3 Standard Edition on a Server with 64 Bit W2K3R2 OS. Are there any constraints or problems known? I take the 64 Bit OS because we want to change the Exchangesystem to Version 2007 when our thirdparty UMS System are ready to connect whit Ex2K7. Thanks FILUE

that is not a supported config http://www.microsoft.com/technet/prodtechnol/exchange/2003/sysreqs.mspx "Note:Exchange Server2003 does not run on 64-bit editions of Windows Server2003. Exchange Server 2003 management tools for remote administration can be installed on a computer running Windows XP SP1, Windows XP SP2, Windows Server 2003, or Windows Server 2000 SP3"

Hey,thanks for this clarification. I take the 32 Bit OS.filue