64 Bit Windows registry and 32 Bit programs

32 Bit programs under 64 Bit Windows have their own (32 Bit) view of the registry. In fact under 64 Bit Windows 32-bit and 64-bit COM registration and program states are seperated. You find the HKEY_LOCAL_MACHINE\Software node under HKEY_LOCAL_MACHINE\Software\WOW6432Node .

Also see the Microsoft Knowledge Base or this blog article.