I would recommend that you read the Product announcements Guide very carefully before upgrading to either DP 8 or 9. DP 8 has had multiple problems mostly involving the IDB (brand new IDB type), and from DP 8.1 onward, there are new licenses required.
I don't know where the previous responder was getting his information, but the Platform support matrix for DP 7 does show Windows 2012 and W 2012 R/2 as being supported
pg 3
If you can't get a disk agent and/or a media agent to install on a Windows 2012 system, we would need to look at the error