My life, My work, Its always an Adventure

So you want to install SP2 (or SP1) for Exchange 2007 and you run into a error message? Then this may be the Problem:

Organization Preparation
Failed

Error:
Active Directory operation failed on dc01.domain.info. This error is not retriable. Additional information: An attempt was made to modify an object to include an attribute that is not legal for its class.
Active directory response: 0000207D: UpdErr: DSID-03150F9C, problem 6002 (OBJ_CLASS_VIOLATION), data 0
An object class violation occurred.

If you look into the exchange setup log of Exchange 2007 then you could find something like this:

[12.07.2009 10:30:40] [1] [ERROR] Active Directory operation failed on SERVERNAME.FQDN. This error is not retriable. Additional information: An attempt was made to modify an object to include an attribute that is not legal for its class.
Active Directory-Answer: 0000207D: UpdErr: DSID-03150F9C, problem 6002 (OBJ_CLASS_VIOLATION), data 0

If you go up and try to see where it starts then you could see:
[12.07.2009 10:30:39] [2] Setting Exchange version of object "Settings".

Then you have Probably installed a Fax Software (I would also bet the Ferrari Fax Connector ). The Problem with this is, that the Fax Software (or at least the Connector) has configured his settings under the Administrative Group in AD. This Object cannot get updated with the SP1 or SP2 because its not from Exchange and the SP1 or SP2 wants to upgrade everything under his structure.

Solution:
Uninstall the Fax-Software (Ferrari Fax Software mentioned also something like uninstall the Fax-connector)
Install Service Pack for Exchange 2007
Then install the Fax Software (Connector) again

If something does not work or it helped you, then please let a comment!

If you want to check this in AD:
open adsiedit and go to: configuration > services > microsoft exchange > Exchange Organistation > admin group > exchange admin group > servers > SERVERNAME > settings.