I was reinstalling yaws on my cygwin environment on windows 7 and the generated yaws script from the yaws.template had two strange lines in it.

line 5:   erl=""/cygdrive/c/Programme/erl5.9/bin/erl"
line 23: werl=""/cygdrive/c/Programme/erl5.9/bin/werl"

you can see that there is an extra quotation mark at the beginning and a square at the end. I tried to see where that comes from but to no avail. yaws.template seems very fine, at least to my eyes.
So i hat to remove the extra characters manually to make it work.
Just for your information, to all the people who have to deal with windows anyhow.