[SOLVED] Identifying 32bit/64bit programs

How does the Windows (Program) Installer distinguish 32bit programs from 64bit?
I have a suite of programs that went into Program Files which I wouldn't have expected to run as 64bit.

It would be my guess that the process is automated. Some programs that are clearly 64 bit ones (some AV's & other programs that are 64 bit only) goes straight into the Programs Folder.

However, many goes into the Program Files (x86) folder because these programs are of the 32 bit type, although they run fine on 64 bit computers. This list of programs are typically longer than the regular Program Files folder. As time goes by, you'll begin to see more programs go to the Program Files folder, rather than the (x86) one, as more programs converts to 64 bit.

However, that may be some time away, as long as there's 32 bit OS's being supported, there will continue to be 32 bit (x86) programs written. Hopefully, the next release of Windows will be 64 bit only.

My answer may not be the perfect one, but that's how I understand it.

Cat

The question was
How does the Windows (Program) Installer distinguish 32bit programs from 64bit?

What is present in programs that run as 64bit programs to identify them?

A text string? At the beginning? A binary indicator?

I think you are confused. The Windows Installer has nothing to do with it. YOU, the user must decide if you run 32-bit or 64-bit then YOU the user must download and install the correct version.

The program developer may bundle both versions in a single download, but then it is that program's installer that then check to see what version is needed.

In most cases that is true, however if you were running W7 64 bit and upgraded Internet Explorer to IE9, the update actually updated the IE9 in the program files (86) folder and the program files folder.

No. You are talking something different, but it is not exactly correct either. If you install IE9 on a 64-bit Windows, you get both 32-bit and 64-bit IE9. As you noted, the 32-bit version is installed in the "Program Files (x86)" folder, but the 64-bit version is also installed in the Programs Files folder.

I knew that, what I am saying is if you run W7 64 bit and updated from IE 8 to IE 9 the update would update the 32 bit in the 86 folder and it would also update the one in the programs folder .

Bsomers.
As you surmised, it is in the program (binary) string. in the program header..

The first value in the file header tells you the architecture:
0x14C for x86 or
0x8664 for x64.

Sorry, but I don't feel confused. I asked how 32-bit and 64-bit routines can be distinguished.

I ran the Installer of a program suite that stems from a well-known magazine. There is only one version of the installer. I expected this suite to land in /Program Files (X86), but found it in /Program Files. That led me to wonder how either the Windows Program Installer or the third-party program's installer, or whatever else, decides that the programs can run as 64-bit programs. That is why I asked how programs that can run in 64-bit mode are distingished from those that cannot.

BTW, the Windows Installer is very sloppily named. Or, let's be kind and say hastily named. It doesn't install Windows. It is a Windows facility for installing third-party programs.

Thank you very much. That is what interested me.