I'm looking for a Visual Basic project that reads text from a window
using the pixels on the screen. So, for example, if the word "Google"
is displayed at location 100, 400 in Arial 10 point font, I want the
program to look at the first letter, determine it is a "G", next an
"o", etc. Does any code for such software (in Visual Basic) exist?

try searching google for a visual basic project involving an ocr, or
optical character recognition

Yes there are methods for OCR, I have experimented with OCR
personally. I have found a good example posted on PSCode.com (Planet
Source Code) that will read and output the defined font.
In my experimenting with this, 
I modified this code so that instead of the text demo, it outputs a
BitBlt region to the PictureBox which will try to match pixels with
the defined font and color.

The OCR example that I used is here: 
http://pscode.com/vb/scripts/ShowCode.asp?txtCodeId=48585&lngWId=1

The example above puts all matches for a defined color into an array
(array height depends on the defined font) and tries to match the
array to the predefined array of letters to that font.

The tricky part of this method is that your positioning has to be
perfect with the font you want to use, you need to match up your scan
region with the font it scans (the text demo inside the program is
good for comparing with this).

I hope this helps. There are many other examples on that website that
may provide the information that you need.