As it was previously noted it's unlikely that any WindowBlind created pre-Vista will work correctly with Windows 7. There have been numerous updates to WindowBlinds since Steve Grenier's Mac OS X Tiger skins were created and it doesn't appear that he issued any updates since 2005. Since then we've seen major OS releases in Windows Vista and 7, which implemented a number of changes in the user interface that was Windows XP or 98.
I've been using Object Desktop since 2000 and although I've found a number of skins that improved the look of Windows 98, ME and XP, many of them were not updated for Vista or 7 and actually look pretty bad on these newer systems. If you're looking for a Mac-like interface and you're running a recent version of WindowBlinds consider using the Sabertooth skin (which comes with WindowBlinds 7) or the Leo skin (which came with WindowBlinds 6).