OAv2 should be fully UTF8 compliant - please use this rather than Open-AudIT v1.
Run the OAv2 audit script like this:
cscript audit_windows.vbs . submit_online=n create_file=y
and you should have a text file produced in the directory you are running it from. It should be fine and if you want you can either run audit_windows.vbs without arguments (assuming you have set the url variable in the script) and it should submit to the server or copy the text from the file and in the web interface, go to Admin -> systems -> Add a system. If you do the second, you should see any errors thrown - of which there will be none because I write perfect code