Normally you'd go to the PC manufacturer for the driver, but since you've tried that, I would go into Device Manager, r-click the card that's showing the yellow bang, delete it, and reboot. Depending on the OS and other circumstances, when the card gets detected as a new device, there's at least a chance it'll install properly. On the other hand, since you've already done the normal driver update thing unsuccessfully, you could skip this step.
Then go here http://support.creative.com/Products/product_list.aspx?catID=1&CatName=Sound+Blaster# - you might have to click the link "Learn how to identify your product" to get an exact model, or just select it from the list if you know it. Some hardware manufacturers are really good about providing drivers to Microsoft Update, which makes the automatic update feature work like a charm, and others hope you will get frustrated enough to buy a new card. (And IMO people should factor this into their buying decision next time they need a sound card).
And my last piece of wisdom is that it appears this motherboard has built-in sound? If so, you could always use that instead, with a driver that probably intalls automatically but if not can be found here http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&keyword=%22D865GLC%22. You might have to change the BIOS setting to enable the on-board audio.