I got the white screen on upgrade problem when I installed on my test board.
I moved the main.inc.php, themes, and umm the other one, prior to uploading the includes directory so overwrote them.
Once I replaced them with good versions they worked.
To me it looks like that might be the issue here too.
I'm on WIN2K with IIS running as well.
Also you'll want to get rid of that trailing slash, that'll goof up pretty good on IIS.
Just some thoughts.
