Just gotta slap them around sometimes. Good work Merry Recording and a Happy New DAW. 

I run my onboard in tandem with my audio interface. In order to do this without issues, they both need to be online and then go to "Change sound card settings" in Win 7. You will see them both there, and at that point you need to assign the onboard audio as "Set Default"
 
This will lock Win7 into the onboard audio even when it sees the audio interface power on/off (which I do frequently). That way the interface is always free and clear of Win7 to allow another program (i.e. SONAR) to use it in ASIO mode.

Thank you Mettelus i will keep that in mind, you have been very helpful.

What Mettelus say's is only true with some set ups. Plenty of people have both on board and a Audio interface co-existing happily together. But there are also many of us who had to obliterate all signs of our on board audio to get things to work properly. 
If your computer is only used for DAW this is not a problem. I disable all windows sounds anyways. There's no need for having 2 sound cards/ 2 sets of speakers anyhow unless you want to proof your songs though cheap computer speakers. 
 
If I turn my audio interface off there is simply no sound. I can turn it back on with Sonar open and Sonar just asks if I wish to use it.