I'm not trying to encourage anyone to buy a game again that they already purchased before. That said, if you really want a version of SH3 that loads and plays without hiccups on Windows 7, get the download version from Direct2Download.
I misplaced my disk a few years back and bought the game again online. The D2D version loads onto Windows 7 and plays just fine. The D2D version seems to be missing whatever stuff is conflicting with Windows 7.
No problems at all.
