I fought the "no textclasses found" problem all weekend and just now got it fixed.
I used the MS windows wiki-wiki installation (several times) and always got the same textclasses error. However, I finally got lyx to work !! My problem was that I had two other versions of Latex on my system (PCtex and Texlive) So I removed these from my path environment variable, plus I removed some environment variables that were related to these two programs. By now I had the detritus of several failed installations on my system. I searched for all copies of textclass.lst on my system, deleted them all, and reran configure.py Now Lyx runs. I hopes this helps someone...
