Hi,
Please be informed that any hardware device needs a driver software to run within a PC, and the driver software depends on the Hardware Make/Model and the Operating System software you are using in your PC to operate it.You will get the Driver software of any hardware within the CD provided with the hardware part at the time of its purchase. The hardware may be an entire PC,Laptop,VGA card, sound card, LAN card etc.
If you do not have the CD or misplaced it somewhere then you need to download the driver software to get going. Thus you need to know all the above information to get the exact software your PC needs. As you have not mentioned the Hardware Make/model and Operating System you are using, i am unable to give you the direct download link.
However you can download the same by visiting the 'software downloads' section of the website of the hardware brand you have purchased. You just need to Google the name of the brand and visit their website and search for the download section.

If you feel that, my answers have helped you getting solution to your problems then please give a vote.

Thanks.