We properly uninstalled Exchange 2010 from a server but it is still appearing within the Exchange Management Console of the other Exchange 2010 server. How can we remove this server from the Exchange organization?
You'll want to get your ADSIEDIT out... Beware - you can break things - badly if you aren't careful. Have a look at the ADSIEdit portions of this...
It's really not as scary as it sounds... Just be careful, you probably wanna back up your system state (AD) before you do this.