Checking the card specifications on the Onkyo Japanese website they list the recommended O/S as:-
Windows 2000 Professional SP3
Windows XP SP1
Although at the present time Windows 2000 Professional is now at SP4 and Windows XP is at SP2.
As I am using an online translator to convert Japanese to English the converted language can be slightly odd!

There was also a note on the website relating to the O/S Windows 2000:-
>>*2: With 24bit/192kHz output correspondence of application is necessary.
With *windows2000 it becomes the correspondence to 24bit/96kHz depending upon the restriction of OS.<<
Harryo