Hi Any one advice me Why shouldn't you install Exchange on the same machine as a DC? Thanks Vijay

check this and many .. you casn however install on DC http://www.petri.co.il/problems_with_exchange_2003_installed_on_domain_controllers.htm

Here are the few reasons : 1) PERFORMANCE ISSUE 2) AD SERVICES take a long time to start up. but exchange services take comparitively less time so if the echange services starts before it then it will not be able to detect the DS server and will give you DSACCESS errors etc.. it wouldnt find the configuration dc etc.. though its on the same server... if for some reason there occurs an windows error or problem on the OS. this will create problem on the Exchange too... if you dont have multiple DCS.. then this will be a big pain if.. your DC goes down.... Please refer this one if you want more reasons http://hellomate.typepad.com/exchange/2004/02/exchange_on_a_d.html If you need any additional information, please feel free to get back to us. We would be glad to assist you further.Viral R

Hi 1. LDAP and other Port Conflict may occur. 2. Memory of server is limited. Harddisk I/O and memory will affect performance. 3. It is hard to disaster recover. If you install them separately, you just want to recover one. 4. Security and permission issue. Please 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.