Hi.
There’s a troubleshooting list bannered to the top of the forum with the most common tips.
If you want to get rid of FxSound, your best bet would be to either manually remove the FxSound Audio Enhancer driver from Device Manager, or to use specialized uninstall software like Revo Free Uninstaller; restart your computer; and perhaps roll back the driver of your main audio device to its former state - at your own risk, of course.
Copied from the FxSound licence header,