Can't save database default locations in SQL Server

I'm trying to change the default directories for data and logs using SQL Server Management Studio. I change the path then click ok but it always reverts back to the old directory in Program Files. Anyone else seen this bug? I'm using SQL Server 2012 Standard.

I do see that the correct values are saved in the registry, but they aren't being obeyed by the studio or other connecting applications that would create new databases.

According to Microsoft, you must restart the SQL Server service for this to take effect.

You can do this easily via the Configuration Manager, or via the services.msc snap-in if you prefer that.