You don't install SSMS "over" SQL Server. You need the version of SSMS at least as new as the version of SQL Server you connect to.
>Hopefully you can get this resolved. The person in that thread tested the exact scenario (installing SSMS 2012 over SQL Server 2008 R2) and didn't run into any issues.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer