If you don't find the compatible drivers in the Device Manager, the Sound card manufacturer website is the most appropriate download site. Every computer or motherboard maker... has a downloads link in their website, where you can search for the right drivers according to computer or motherboard model... if you don't know the computer specifications, install a system information program such as Speccy, Everest, Aida, Astra32, etc. and under Audio (may be; sound, multimedia, or even under motherboard) you will find the Audio card model to download the correct drivers.