Cannot choose ASIO driver

Nice job with MS4

but it seems so CPU demanding that both when I insert notes with my keyboard and with the playback the latency is so high that it is impossible to work with, and even if I wait the 4/5 seconds for the playback to start the result is an awful glitchy mess.

I think the main problem is that MS is using the lame integrated sound drivers, while it seems I cannot choose to use my ASIO drivers (focusrite asio, to be more precise).

Is there anyway to fix this problem?

MAny thanks