Uhh, so what should i have done then?
First of all it's good that you brought this up, apparently the tutorials section needs to be updated with new threads. To provide an answer to your original question regarding winRAR not recognizing the numbered archive files, there are a couple ways of doing this. First, you could open the winRAR program itself and drag & drop the .001 .002 etc files that extract from the archive files you downloaded into the winRAR user interface and click the big 'ol "Extract To" button. (Don't rename any files or any of their extensions, this will just mess up the process) What I recommend doing is right-clicking on the .001 file that comes out in Explorer and going to Properties > Opens with [Click the Change... button] > If winRAR isn't listed in the box that comes up, hit Browse > navigate to the folder where winRAR is installed, select the main executable and hit Open. > OK > Apply/OK. Now you should be able to double-click the .001 file and it should open up in winRAR, allowing you to extract it anywhere.
I don't have any of the RAR files from 128bit, so I just used a file I had lying around for the example. The steps should be the same. If this isn't clear enough or if you run into another problem, feel free to ask.
Oh by the way, the .sfv files are files that allow users to check the integrity of the downloaded files. You don't necessarily have to mess with those unless you want to be sure that the files aren't corrupted from the download. (Which can happen on rare occasions) You can use any free SFV file checker program to use them.
I hope that helps answer your questions. Again, feel free to ask if it doesn't.