You need the Xonar patch from the Vista section of the Asus driver
If you can't get IE to work just uninstall the new Xonar driver first and reboot. Then reinstall the Xonar driver but before you reboot,...install the patch, then reboot.
It's right at the top of the Vista Xonar driver page, small patch only takes a second to install. The patch fixes a bunch of problems with the new Win 7 Xonar drivers
, like Explorer and the Control Panel not working correctly after installing the Xonar Win 7 drivers.