Hi Guys, Sorry for the stupid question, Can I deploy the OCS on my existing Exchange 2003 system and how? Thanks.

You can deploy OCS in your environment with Exchange 2003 as it does not require Exchange to be in place. As for how, you will have to update AD schemas and then install OCS.

Hi Michael, Thanks for your prompt reply, can you share some document that helps me to set up this scenario step by step? Jay.

Since we only discuss pure Exchange problem in this forum, I suggest you create a new thread in OCS forum. Thank you for your understanding. Meanwhile, I would like to share you the following articles about OCS 2007 requirements and installation. OCS 2007 R2 Hardware and OS requirements http://blogs.technet.com/b/ucedsg/archive/2009/01/16/ocs-2007-r2-hardware-and-os-requirements.aspx OCS 2007 Install – Step by Step http://blogs.technet.com/b/rogulati/archive/2009/04/08/ocs-2007-install-step-by-step.aspx Thanks. NovakPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.