How to upgrade MS Windows Server 2003 Domain & DNS (32 Bit) to Windows Server 2012 (64 Bit) version ?

There is some information was missing. Finaly I got best guide and successfuly I migerate our server2003 Server to201264Bit.

a)     http://blogs.technet.com/b/canitpro/archive/2013/05/05/step-by-step-adding-a-windows-server-2012-domain-controller-to-an-existing-windows-2003-network.aspx

b)    http://blogs.technet.com/b/canitpro/archive/2013/05/27/step-by-step-active-directory-migration-from-windows-server-2003-to-windows-server-2012.aspx

Upgrade will not take place becouse OS Bit Version is different. Server2003 domain is running on32 bit & you want to upgrade on Server201264 bit version. So, yu will need to cleen installation if   you required  domain on server201264 bit.

I have find it for you

 http://msmvps.com/blogs/mweber/archive/2012/07/30/upgrading-an-active-directory-domain-from-windows-server-2003-or-windows-server-2003-r2-to-windows-server-2012.aspx    

best of luck.....!

Many Thanks. Muhammad Tahir