Hi, I have read two previous threads that relevant to my question: http://social.technet.microsoft.com/forums/en-us/configmgrgeneral/thread/982CCA99-C622-4203-A9EF-39539E35DC87 http://social.technet.microsoft.com/Forums/en-US/configmgrgeneral/thread/0d187151-ced6-4eb3-b9e7-4de1b40889d6 However, my scenario is slightly different. We have a single domain, multiple sites AD. Currently, we have SMS 2003 SP3 implemented. One primary at central site and one secondary at each remote site. All boundaries are defined by the AD-site and all site serveres are published to AD. Now we are undertaking an infrastructure renew process. What we are planning to do is this: 1. create new AD sites and install SCCM 2007 in new sites and publish to the AD. 2. All the new servers and new clients will go to the new sites and managed by these SCCM servers. 3. some existing servers/clients may move from old sites to the new sites 4. when all old servers/clients de-commissioned we will then remove old sites (including existing SMS servers) from the AD. My concern is in the first two or three stages we will have SMS 2003 and SCCM 2007 running side-by-side or co-exist in AD. Although SMS servers and SCCM servers cover different AD-Sites thus should have no boundary overlap, they both publish to AD. Will this be/cause a problem? Thanks in advance,