SAP on Window 2008 R2 (Downgraded)

Hi

We have installed the SAP below software at our production site. Now we are in process of setup the DR system.

1. SAP Software     : SAP ECC 6.0 EHP5 / BW 7.3 / GRC 10.0
2. Database         : Oracle 11.2.0.3
3. Operating System : Window 2008 R2

The challange is that now Microsoft is not selling/giving Window 2008 R2. They are giving "window 2012 standard" license and suggest us to downgrade the same to "Windows 2008 Enterprise Edition".

Question: Please let us now that does this downgraded version will work at DR and there should not be any problem due to this.

Please clarify it

Regards

Vimal Pathak