The process to install an RTL-SDR dongle on Windows involves the simple step of running Zadig and installing the generic WinUSB drivers to the RTL-SDR, which shows up as "Bulk-In, Interface (Interface 0)" in Zadig.

However we find that people sometimes accidentally use Zadig to install WinUSB to "Bulk-In, Interface (Interface 1)" by mistake. Installing WinUSB to this interface can break your installation, and it can cause the RTL-SDR to display a "usb_open error -12" on command line software, and can cause problems connecting to the device on GUI software like SDR#.

Over on YouTube Corrosive from the SignalsEverywhere YouTube channel uploaded a very useful video that shows how to fix this problem.