What Audio driver?
Could be that an ASIO 'always On' driver or such has been initiated by launching the program.

For what it's worth I often use a W7 64 AMD based system also and I have never seen that. I would notice something using 25% processor right away.

I'm one of those that, when it is time for music, I make sure all un-needed processes are removed/killed and often leave Task Manager open for a few, even if just to see how long it takes to truly settle down.
In recent Beta testing this was normal for me to watch what was happening, performance wise, for both load and unload as well as while running it.. don't recall seeing that behavior at all..


Make your sound your own!
.. I do not work here, but the benefits are still awesome