Audio problem in my hp lap

Hi
I have a recently noticed that my lap speakers are not working but its audio keys are working. i have checked audio settings there is no problem on my audio settings but there is no sound. If i play any music it is showing that " DEVICE IS BEING USED BY ANOTHER APPLICATION.PLEASE CLOSE ANY DEVICES THAT ARE PLAYING AUDIO TO THIS DEVICE AND TRY AGAIN" like that it is showing but there is no active devices on that time after restarting my lap audio is working.when i switch on next day morning again it is showing same as above. recently in my lap audio jack i put my desktop speakers for listening music this will effect my lap. please tell me the permanant solution for this problem