Here's the Prolific website link: http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=225&pcid=41

Direct download file: http://www.prolific.com.tw/UserFiles/files/PL2303_Prolific_DriverInstaller_v1190.zip

After you download the file, UNZIP and INSTALL it until you finished. Then restart your PC.

Troubleshoot:

If nothing happens?, Try "Disabling Signed Driver Signature Enforcement on Windows 8."

Link: https://learn.sparkfun.com/tutorials/disabling-driver-signature-on-windows-8/disabling-signed-driver-enforcement-on-windows-8

Watch this video: https://youtu.be/dpevn9TohXY