Hi there,
crackling, static, audio dropouts etc., can be very frustrating to resolve as they can be caused by many factors. Hardware/software conflicts for resources, hardware used, system configuration, cable routing, bad programming of software and many other variables, so there is probably not going to be a quick fix to resolve this issue.
You could download Latency Tester from here:
http://www.thesycon.de/deu/latency_check.shtml and see if you are getting any major spikes as this could give an indication of the best place to start looking.
If you are trying to run both the on-board sound and the Creative card, disable the on-board chip to see if that makes a difference.
Try running a live version of Ubuntu. If it is a hardware issue then you will still have the same problem within this environment. If it is not present then you can narrow your search to Windows, driver conflicts, and the programs you are using.
If you are prepared to do so, do a clean install of Windows, add the basic drivers one at a time rebooting after each has installed and test your system as you go. If it is the NVidia drivers causing the problem this would show up pretty quickly.
If the problem shows up only when you are doing certain things, such as watching YouTube videos, try changing your Internet browser.
Not sure if any of this will help or if you have already tried these things but hopefully, we can get this sorted for you.
