the game is notorious for having a lot of issues with modern hardware and operating systems (for example issues with multicore cpus, codecs/movies, awful graphics when running on dx10+ graphics hardware and more), so the big question is - what has been fixed?
I have Windows 7 Home 64-bit. All I had to do to get the game to work was to run the game as administrator. The videos run and everything. Maybe it's possible the DLL people are saying needs to be registered had already been registered on my PC from a previous install of Thief I tried to get working a year or two ago. But, all I did this time was install the game, right-click the icon, go to properties, compatibility tab, set it to have administrator privileges, then it runs just as it did when I first played the game.
No setting affinities, no patches.
$10 well spent in my opinion.