Hello, We have an SMS 2003 infrastructure with a single primary site and about 1500 advanced clients. Now we want to do a clean installation of SCCM 2007 R2 and also want to use the same site code ( but we don't want to retain any other old data) that has been used with SMS 2003.Due to budgetary constraints, we have to re-use the same hardware which already has SMS 2003 on it. We thought about below options 1. Remove SMS 2003 advanced client from all client machines using an SMS 2003 advertisement and CCMclean.exe. Uninstall SMS 2003. Prepare AD Schema for SCCM 2007 R2. Format and do a clean install of SCCM 2007 R2 with the same site code. Push SCCM client to all machines. This seems straight forward. 2. Leave exisiting SMS 2003 advanced client on client machines. Uninstall SMS 2003. Prepare AD Schema for SCCM 2007 R2. Format and do a clean install of SCCM 2007 R2 with the same site code. Is this technically possible? Will SMS 2003 Advanced clients talk with new SCCM primary site with the same site code? Thoughts are appreciated. Cheers Lakmal

Is there any reason to keep the existing sitecode? Why can't you use a new one?If there's no way to use another sitecode: make sure to clean up the system manegement container in AD. There's no need to uninstall the SMS 2003 client (because the installation of the ConfigMgr client takes care of it). The existing client won't talk to the new ConfigMgr site (beacause of a mismatch of the trusted root key). So you have to use the RESETKEYINFORMATION client installation property: http://technet.microsoft.com/en-us/library/bb680980.aspx

Now we want to do a clean installation of SCCM 2007 R2 and also want to use the same site code ( but we don't want to retain any other old data) that has been used with SMS 2003. Re-using the same site code is begging for trouble. I would avoid this at all costs.http://www.enhansoft.com/

If I uninstall SMS site and delete the site objects (as suggested by Torsten) from Systems Management container in AD and do a clean SCCM 2007 installation using the same site code, will there be any problems?Possibly, but if you clean the AD and there is no data floating around then you should be ok. In the days of SMS (and I was very green) we moved and used new Hardware and opted to do a fresh install because of the orginal install and we wanted to use the same site code. We deleted everything in the Systems Mangmt folder and confirmed we didn't have any other DC's or any part of the AD with that site code floating around. We then installed SMS again and all the clients moved with no problems. I don't recommended it but I have done it. Before you do it you need to stop all packages and then create a new package and send to all the machines forcing a deletion of all packages. Why? Because when the new site comes up with the same site code you will create a package. This package and the old package will now share the same package number. When the client goes to run it (assuming the same package version .1 then the computer will run this new package. The client will see that it has it in cache (but not really) if it is setup then it could try to kick off the wrong package. Now this was SMS 2003 I am not sure if 2007 is smart enough to recognize that the packages are totally different (hash) but this was a problem so we had to push down and kill all packages from the client machines local cache. If you run everything from the DP then you should be fine.If I push SCCM client with RESETKEYINFORMATION to computers which already have SMS 2003 advanced client, will they be upgraded without any issues?We had only a few clients that just refused to upgrade but this was generally due to WMI or some other isse we had to correct before we could install the ConfigMgr 2007 client. http://www.sccm-tools.com http://sms-hints-tricks.blogspot.com