How to install SonicStage? It's acting up for me, and I think some help would be nice

[SolidSnakeFan]

Okay, I'm new here. I have the JCPSP emulater, and everything in good working condition. But, I am having an issue trying to install SonicStage. My PC type is Windows 8. Every time I try to install it while on desktop mode, it says "Data was unable to be retrieved from the Server". Sometimes it will actually get past there, but during the installation, it will say something like "cannot recieve data", and it won't install. I really want to play Kingdom Hearts Birth By Sleep on my pc! My graphics card is just fine, it's NVIDIA and an i5 . So I think those aren't an issue. I really just want to install the SonicStage, so I can hear the good music of this game!