The problem of synchronization sound card with Cubase!

Guys I have a problem with my sound card(EchoAudioFire4) and Cubase Elements 7. When I run Cubase, it shall issue a notice:
The following channels are in use by another application:
Playback 1
Playback 2
Audio output from these channels will be muted.
At the same time I listen to music in the music player, or turn on the video tutorials. It’s horrible, because I am a novice user and watch video tutorials, but with this problem, this was not possible!By the way, if I switch off the other application, the sound in Cubase appears! I have tried everything, but can’t synchronize Cubase and the sound card.
Thank’s a lot for helpful answers!

P.S.
Here’s my e-mail, just in case: k.slava.1990@ya.ru