Hi,
Method 1:
I would suggest you to refer to the link and try to run the troubleshooter:
Tips for solving problems with USB devices
http://windows.microsoft.com/en-US/windows-vista/Tips-for-solving-problems-with-USB-devices
Method 2:
Refer to the section “Sound from my Speakers is crackled or distorted” in the link and check if it helps:
Tips for fixing common sound problems
http://windows.microsoft.com/en-US/windows7/Tips-for-fixing-common-sound-problems
Method 3:
Try to uninstall and re-install the sound drivers and check if it helps:
Update a driver for hardware that isn't working properly
Refer to the link for more information:
Finding drivers
Method 4:
I would suggest you to disable and re-enable the USB controllers:
a. Click Start, and then click Run.
b. Type devmgmt.msc, and then click OK. Device Manager opens.
c. Expand Universal Serial Bus controllers.
Note: You might have to scroll down the list to find this item.
d. Right click the first USB controller under Universal Serial Bus controllers, and then click Uninstall to remove it.
e. Repeat step 4 for each USB controller that is listed under Universal Serial Bus controllers.
Note: Restart the computer. After the computer starts, Windows will automatically scan for hardware changes and reinstall all the USB controllers that you uninstalled.
Let us know if it helps.