//++++++++++++++++++++++++++++++++++++++++++++
// ENBSeries Readme file
// visit http://enbdev.com for updates
// Copyright 2007-2012 (c) Boris Vorontsov
// Readme by Marty McFly
//++++++++++++++++++++++++++++++++++++++++++++


You sure have the version 2.00 of the game which isn't modable.
Downgrade to 1.00 first.


How to do that?

Google "San Andreas Downgrader Patch", you'll find everything you need.
Modding SA is no magic, it's easy if you use your brain.