Download the Release.zip file. Extract the rtlsdr.dll file to the SDR# folder, or whatever software is using it.
Download the Release.zip file. Extract the librtlsdr.dll file to the SDR# folder, or whatever software is using it. Rename to rtlsdr.dll if necessary (e.g. SDR# looks for rtlsdr.dll instead of librtlsdr.dll)