Have you changed the line in trio.bat which reads "cd %TRIO_HOME%" at all? It appends /docs to the current directory and so this line should be left as is.

Alternatively you can change the following line in trio.xml:

<http-server port="8090"/>

to:

<http-server port="8090" root="C:\\Program Files\\trio-0.1.4.alpha5"/>

Cheers
Paul