FreeOCR is a freeware scanner and OCR program which uses the Tesseract free ocr engine also known as a Tesseract GUI.
Supports opening multi-page tiff's, Adobe PDF and fax documents as well as most image types including compressed Tiff's which the Tesseract engine on its own cannot read. It now can scan using Twain and WIA scanning drivers.
The Tesseract OCR engine is an open source product released by Google. The Tesseract project can be found here: http://code.google.com/p/tesseract-ocr/
Please note that the Tesseract OCR engine requires images at a resolution of 200 dpi or greater and as such it is not suited for reading PC screen shots which are only about 72dpi. For best results scan at 300 dpi greyscale.
Download the bootstrap installer called freeocr.exe. The installer will download all the needed files in order to get FreeOCR completely functional.