scroll down a bit you will see a reply by Den that Oxwall is not compatible with windows server, it must be installed on apache.
http://www.oxwall.org/forum/topic/1503
here is the quote:
DenJul 13 '11
@Michael
It seems that this site is hosted by windows server and IIS, which is not compatible with oxwall requirements. Oxwall can be installed on Apache web server only.
Alan please try to keep posts the same, that way we dont have to do all the background work again :) Thanks buddy
http://www.oxwall.org/forum/topic/11137