TWAIN now has a version 2.0. It does not automatically install itself, but while some drivers do come with it, often many do not. You should find this file if it is installed:
32 bit systems:
64 bit systems:
If that file is not there then you will need to manually download and install it:
1.) Download the appropriate dlls from https://sourceforge.net/projects/twain-dsm/files/
2.) Install them in your appropriate path.