Although Freedom Scientific's Jaws is probably the best screen reader out there, it is very expensive and some of the free software has improved so much over recent years. Here are some links:
THUNDER:
[You must be registered and logged in to see this link.]Probably the best out of the lot. Settings are very simple, but it's worth playing around with them thoroughly before you decide it's not right for you. It can be run from a PC or from a USB memory device. It's very impressive and you get a lot of other smaller apps with it. Give it a try!
NonVisual Desktop Access (NVDA):
[You must be registered and logged in to see this link.]After testing NVDA my opinion is that it is superior to Thunder. It can run from a USB device as well as from your PC.
BRLTTY:
[You must be registered and logged in to see this link.]Primarily for Linux OS, but also promoted for MS-DOS/Windows. I will investigate it further. It seems to provide a fair amount of Braille support for English and French.
There are many other software projects, plug-ins, unfinished open-source, etc out there, but these are the most promising for Windows. I will continue to focus on researching screen readers further and add more here whenever I can.