This one I got from The Official SBS Blog.
If you’re running Windows Small Business Server (SBS) 2008, you don’t want to miss this technical whitepaper: Repair Microsoft Exchange Server roles in Windows Small Business Server 2008.
This section contains repair information for problems you might encounter with Exchange Server in your Windows SBS 2008 network. The following topics are included:
- Reinstall the Client Access Role in Windows Small Business Server 2008
- Reinstall the Hub Transport Role in Windows Small Business Server 2008
- Reinstall the Mailbox Server Role in Windows Small Business Server 2008
The post from The Official SBS Blog also makes an important warning:
Please note that removing and reinstalling Exchange roles on SBS 2008 should not be a common troubleshooting step. These documents should only be used when other troubleshooting resources have been exhausted.