To ensure the card on which you have the USB ports hasn’t gone bad, Please check if the Ethernet port on the rear side of the computer and Headphones jack on the right side of the system are working or not?
I would also suggest you to run the Online USB Diagnostics by clicking on the URL mentioned below:
If Ethernet port and Headphones jack test fail or even the online USB diagnostics fail, then it’s an issue with the Daughter Board card. I would suggest you to send me a Private message with the details of computer like: Service Tag & contact number. Kindly don’t share your Service tag in the open forum.
If both tests pass, I would suggest you to download the Wistron-Driver again and reinstall it from the URL mentioned: http://www.dell.com/support/drivers...
You can also try removing the USB root hubs. In device manager, under USB controller, you will find many USB root hubs, right click on each one of them and click on uninstall, and remove all of them, and restart your computer. Windows will see the "New" device and then try to install the drivers.
If that doesn't fix the issue, then you need to update Chipset Driver. Download and install the chipset driver from the URL mentioned below and restart your computer:
Kindly get back if there are any further queries.
Thanks & Regards