Extending Active Directory 2003 Schema for windows 2008

I am not installing windows 2008, just extending the schema of w2003 AD.
I have been told that in order to use a new GPO templates for vista, you need the AD2003 schem extended.

is this the only benefits?

Yes, extending the schema will allow you to have more flexible of managing your GPOs such as Group policy client side extensions etc. It will allow you do more machine configuration including Vista plus other GPO which required you to do the extension such as wire-auto configuration and port authentication and so on.

Are you trying to use the Wired and Wireless policies?   For that you will need a schema extension
http://technet.microsoft.com/en-us/library/bb727029.aspx
Thanks
Mike

how can you tell that the schema changes has been replicated to all the DC that hold the infrastructure operations master role?

this did it
Schupgr.exe

I am getting this error though.
SSPI Bind succeeded
Current Schema Version is 44
ERROR: Cannot obtain schema version to upgrade to: 1

Are you running the adprep from the Schema Master?

adprep /forestprep
went successful
as well as adprep /domainprep

i din't know about the error message

Version 44 means that your schema has already been upgraded to Windows 2008.  Are there any other errors in your adprep log?  

One thing that I ran into that caused an issue with adprep was McAfee 8.5i.  

Another thing to check would be to run repadmin /showreps to verify that replication is working.

how do you run repadmin.
I did it run it displayed just the help

repadmin /showreps or repadmin /showrepl