To ensure your Windows Vista or 7 computer is optimized to work for audio processing, please follow the link below for a official Microsoft optimization guide:

http://windows.microsoft.com/en-us/windows7/Optimize-Windows-7-for-better-performance

As you may know, almost every personal computer is a unique hardware and software environment. If one or more variables, including a given device driver, in the system don’t interact well with the rest of the system, the result can be undesired performance. Thus, we have provided a USB Audio Issues FAQ that describes what configuration variables numerous users have identified as the root cause of their audio issues. Review the suggestions available at the link below if you are still having audio trouble after optimizing your computer:

http://line6.com/community/docs/DOC-4282