no pdf file generated (windows version 2.7.8) and point and click not working anymore

[Katrien de Vos]

Until recently the windows versions of lilypond generated pdf-files. In 
one of the last versions point-and-click didn't work anymore. Now only 
.ps files are generated but not pdf-files. I downloaded an older version 
(2.6.3-1) but this one didn't work either. Has anything changed or is my 
windows setting different.
As far as I know I have only made changes the set-variable because I 
installed python (which I need for using convert-ly.py).

Jaap