I am sorry, this question seems so elementary, but I'm baffled and could not find the answer by searching.

I am running Windows 7, 64 bit. I purchased a hard copy of Dishonored and followed the installation prompts, which appeared to install the game in part via Steam. I saw no prompts which might let me choose how to install the program. My Steam application is 32 bit (in the Program Filesx86 directory). When Dishonored installed, all files went into the Steam directory, and when the program runs, the task manager shows the process as 32 bit.

My computer uses a quad-core processor, so my understanding is that I do not have optimum performance for 32 bit programs. In fact, Dishonored does run slowly when I have to load a save file or a new area. Sometimes blinking into a distant area causes slow-downs also.

This may seem naive, but the box says "Enhanced for: 64 bit, multi-core." Doesn't this mean I should be able to install/run the game as a 64 bit program?

Any ideas?

Yeah, I have no idea what they mean by this. Dishonored is a 32-bit piece of software, so you can't run it in 64-bit. Maybe it run slightly better on 64-bit computers thanks to DirectX being 64-bit or something, but I don't know.

This is a common issue with AMD Radeon cards, so I guess that's what you have?

Thanks Freddo. I assumed from the box that it had both versions. Any insight into why it specifically says "Enhanced for: 64-bit" on the back of the box?

Also, I have resolved most of the slow-down, at least on medium graphics. My laptop had decided Dishonored needed to use its power-saving graphics card for some reason... (For people with this problem, Right click desktop> NVIDIA control panel> Manage 3D settings (left hand column)> Program Settings tab. Now, click "Add" and navigate to the Dishonored exe. Mine was in D:\Steam\steamapps\common\Dishonored\Binaries\Win32.)

Are you 100% sure? I'm asking, cause I found these keys in Windows registry:

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Arkane\Dishonored]
"Install_Path"="...\Steam\steamapps\common\Dishonored RHCP"
"Exe_32_Path"="...\Steam\steamapps\common\Dishonored RHCP\Binaries\Win32\Dishonored.exe"
"Exe_64_Path"="...\Steam\steamapps\common\Dishonored RHCP\Binaries\Win64\Dishonored.exe"

But my game doesn't have Win64 folder.

You know, that is a darn good question.
And good find on those registry key entries, along with the "Enhanced for: 64 bit, multi-core." , it does make you wonder if there was a Win64 folder and was removed at release for some reason.

I just checked and i only have a Win32 folder also.
So i dont think anything is "wrong" with your version as I had no option while installing either.