In Vista, What is the difference between "Program Files" and "Program Files (X86)"?

Discussion in 'Windows, Linux & Others on the Mac' started by spaceballl, Feb 22, 2008.

  1. macrumors 68030


    Nov 2, 2003
    Silicon Valley
    Hey all,

    I run the 64 bit version of Vista on my work PC / virtualized mac, and i've just been noticing recently that now in Windows there are two Program Files folders. I can't figure out how windows decides which programs get installed to which directory - any ideas? thanks!
  2. macrumors newbie

    Sep 17, 2007
    My understanding is that any 32bit applications will be installed into the "program files (x86)" folder where 64 bit apps will be installed into the regular "program files".

    As for other differences, I'm not sure.
  3. macrumors 68000


    Jan 18, 2005
    Yep - all 64-bit versions of Windows (including Server 2003/64) have separate locations for 64-bit and 32-bit applications. Windows will automatically select a destination directory dependent on the application - this doesn't stop you installing to another location if you prefer.

    Resist the temptation to try and force everything into a single 'program files' directory, though, as there's potential for problems if you do so.
  4. thread starter macrumors 68030


    Nov 2, 2003
    Silicon Valley
    Okay thanks for that - very weird. You'd think they would just call one folder "Program Files (32 bit)" and the other "Program Files (64 bit)" - that would have prevented me from needing to ask the question!
  5. macrumors regular

    May 19, 2007
    That's true. I wouldn't try to rationalize Windows. :)
  6. macrumors 68040


    Oct 25, 2004
    It gets worse!

    I was involved in a project a while ago to update some software to run under 64-bit windows. There's a standard folder called System32 under the Windows folder for system-wide .dlls (and other types of files).

    I was amazed to find that under 64-bit Windows, the folder becomes:

    System32 - for 64-bit processes
    SysWOW64 - for 32-bit processes

    Yeah, 32 means 64-bit and 64 means 32-bit!

    Nice, MS, really nice!
  7. macrumors 65816


    Dec 9, 2006
    North-East, UK
    Is there a "run64.dll" now or is it still "run32.dll"?
  8. macrumors newbie

    Nov 12, 2008

    can i delete one of the program files i have a 64 -bit vista ultimate and i have a program files and a program files x86..... can i delete either one of them .....
  9. macrumors 68000


    Mar 28, 2007
    No, you shouldn't do that.
  10. macrumors 68000

    Jul 14, 2008
    No.......don't delete either Program Files folder, or the Windows folder.

    Oh, and if anyone is wondering why System32 for for 64bit stuff and WOW64 goes to the 32bit files, it's because awhile back devs got lazy and never bothered to code their programs so that they could deal with System32 having a different name, so rather then pointing to location or folder, the programs literally are sent to "System32". Changing it to "System64" would break all of those. As for WOW64, they were making the directory used by Windows On Windows 64bit, so they called it....WOW64, apparently never realizing how weird that looked next to the 64bit System32 directory......

    Ahh, Microsoft...

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