No Sound Except in Cubase

Ok, I usually deal with many problems but this one’s got me.

I closed CB S5 and now have no sound on my computer EXCEPT in CB and the Microsoft sound screen that has the test button. I changed my preference for CB to release the driver when in background and still nothing!
The device manager says that my sound card driver is working. (well of course it is) Nothing else plays except for CB and that test button.
It seems I started having shut down problems ( hanging up and sometimes going to bs) since I installed CB6 demo and Halion 4 demo. Any ideas anyone? Would be appreciated! Thanks.

Will

Hmmm. No ideas on this problem?

How do internet sites like youtube respond? Does everything work before you open Cubase?