go outside of the PC tower with your card at least.
Past that a better driver for it will help. many USB sound cards will also have updates on their websites even though you just bought the thing new... so do look there too if you go USB sound card.
Past that... an independant USB DAC/Sound card driver like the german version sold for $70 or so will really help too.
A DAC with USB if money permits is also a thought.
In any case... DAC or Card... the better, the better. Apogee & Lavry make some nice units for under a grand with lots of flexibility and fine support.