I have an HT Omega Striker 7.1 sound card.
But regardless of the brand of sound card, if you uninstall a driver
(actually a driver or program for anything) you need to restart the PC before reinstalling. If you don't restart before reinstalling, results can be iffy (and if there was a problem, the problem may still be there).
If you are having problems with the HT sound card, contact their support. I've had good response from them.