Fix error determining whether the target environment requires adprep in windows server 2012, during domain controller promotion

Is your forest/domain functional level at 2003? You should be able to add a 2012 domain controller into a 2003 forest - provided the forest is at the 2003 functional level.

edit: Also, check your DNS settings and make sure they are correct and that you can resolve the proper srv records to locate the domain controllers

edit2: If you are trying to install a RODC, you will need to have a 2008 writable DC to install a read-only DC.

If all your domain controllers are at least Windows Server 2003 and both your domain and forest functional levels are set to at least Windows Server 2003, adding a Windows Server 2012 DC should work fine:

http://technet.microsoft.com/en-us/library/hh994618.aspx#BKMK_FunctionalLevels

The only situation where you'll need at least a Windows Server 2008 DC is if you're adding a read-only domain controller.

Edit:

If the message you are getting is the one shown here, then it's only a warning (as should be clear from the yellow exclamation point icon); it will not stop you from continuing, unless you're actually trying to install a RODC.