Just to follow on from MJRBIM's post, if you are trying them out in Word you will need to choose Edit -> Undo AutoFormat after typing the asterisk at the end, since Word will automatically convert anything between asterisks into bold text, which is useless for barcodes. We use a font called FRE3OF9X.TTF here, and we've had pretty consistent good results with it. Google the name and you should find it quite easily.
If you need to fit the barcode field into a certain width but find you still cannot scan it, something we have tried is adding the field to the report more than once and overlapping it slightly vertically so that the field becomes taller without expanding horizontally - changing the font size would not do this.
Hope this helps
Geraint
The lights are on but nobody's home, my elevator doesn't go to the top. I'm not playing with a full deck, I've lost my marbles. Barenaked Ladies - Crazy