Having problems installing 64 bit Win7

Discussion in 'MacBook Air' started by PhazonUK, Nov 25, 2011.

  1. PhazonUK, Nov 25, 2011
    Last edited: Nov 25, 2011

    PhazonUK macrumors 6502

    Jun 1, 2010
    I'm trying to install Windows 7 Professional 64-bit onto my 2011 MacBook Air and it's having none of it.

    The problem seems to be the 64-bit ISO. I have downloaded it from 3 different sources now (MS student site with my uni, torrent site, and official MS site) and all 3 have problems when it comes to mounting them and/or writing them to the USB drive.

    On Windows I'm mounting them using Daemon Tools Lite and whenever I try to run it Windows gives me errors about corrupted files. On OSX it just won't mount at all.

    I had no problems installing 32-bit Windows 7 using the exact same method.

    Can anybody help me out? Been trying this for hours now.

    EDIT: Thought I'd mention, the only reason I'm wanting to install 64-bit is so that I am able to use all 4GB of RAM when using Windows 7 as at the moment we are stuck with 2.7GB (I think).
  2. newdeal macrumors 68020

    Oct 21, 2009

    i had no issues. i didn't have the original iso but I did have a dvd I burned from it so I used disc utility to make a dvd master of it, that made a .cdr file. I renamed that to change the extension to iso and it had no issues writing that to a flash drive
  3. monkeybagel macrumors 65816

    Jul 24, 2011
    United States
    Have you performed an MD5 of the ISO files to make sure they are the same?

    I assume you are trying to run the installer from the 32-bit version of Windows 7 Professional that you mentioned - it is normal to get the "Setup is not a valid Win32 Application" error because it is 64-bit code.

    Are you following the Boot Camp install wizard? You can't "upgrade" from the 32 to 64 bit directly. You will need to back up your files and do a clean install. I would recommend backing up your Windows files, deleting the Boot Camp partition using the Boot Camp Assistant in OS X, then running it again to recreate the partition and to make the USB drive from the ISO file that you have, ideally the official one from Microsoft.
  4. PhazonUK thread starter macrumors 6502

    Jun 1, 2010
    Got it working now.
    Boot Camp Assistant kept failing when copying the ISO contents to the USB drive so I tried copying them manually and it worked fine.

    Oddly, all 3 versions I downloaded are different sizes. In the end it was the official MS ISO that I used.

    One more thing, are there any issues with 64-bit Windows on the Air? Do all the drivers work properly?
  5. monkeybagel macrumors 65816

    Jul 24, 2011
    United States
    Yes - it seems to work great. I installed Windows 7 Enterprise x64 and the drivers installed just fine. It does not use AHCI so I don't think it supports TRIM by default, but this is by design of the Boot Camp drivers. There are some workarounds, but I think they cause problems (like sleep problems).

    But in short, yes, it works great.
  6. johnhurley macrumors 6502a


    Aug 29, 2011
    Most everything seems to work just fine.

    The keyboard always stays lit after booting in to bootcamp and has to be turned down manually ... or in other words no integration between the light sensor and automatically turning off/down the backlighting.

    I cannot think of more than that right now.

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