Question : Add Small Business Server to Existing Server 2003 Domain

I have an existing Domain with two 2003 R2 domain Controllers and one 2003 member server; one of the domain Controllers is running exchange 2003. I need to add Small business Server 2008 Premium and migrate Exchange.
Is this possible?
Any special steps?

Answer : Add Small Business Server to Existing Server 2003 Domain

in order to check and fix error for booting in Mc OS: see below solutions
•    "Press X during startup" = Force Mac OS X startup
•    "Press Option-Command-Shift-Delete during startup" = Bypass primary startup volume and seek a different startup volume (such as a CD or external disk)
•    "Press C during startup" = Start up from a CD that has a system folder
•    "Press N during startup" = Attempt to start up from a compatible network server (NetBoot)
•    "Press T during startup" = Start up in FireWire Target Disk mode
•    "Press Shift during startup" = start up in Safe Boot mode and temporarily disable login items and non-essential kernel extension files (Mac OS X 10.2 and later)
•    "Press Command-V during startup" = Start up in Verbose mode
•    "Press Command-S during startup" = Start up in Single-User mode

if you have no choice for this then, please use Mac DVD an reinstall is best solution.

have fun