Maybe, 'installing' (I guess, it is only copied in a folder, anyway) Python 2.5 as well, could help.
I have both 2.6 and 2.5 on my C: partition, and both exporters are working.

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt