Skip navigation
This discussion is archived

27in iMac (late 2009) ATI 4850 drivers problem in Windows 7

22212 Views 20 Replies Latest reply: Jan 6, 2011 7:46 AM by Steven Richason RSS
  • ViperrepiV Level 1 Level 1 (0 points)
    Seconded....I have the color banding problem in bootcamp/win 7 64 bit. I would really appreciate a more detailed walk-through. Sounds like the mobility drivers are the way to go?
    iMac 24 in and Macbook Air, Mac OS X (10.5.6)
  • --amski-- Level 1 Level 1 (0 points)
    I struggled with this for ages, then found that for the drivers I had used a Snow Leopard DVD (a retail DVD, I think), but not the one that came with the particular iMac. If you use the disk that came packaged with the particular iMac, the drivers should work out fine, in my experience.


    iMac 27", Windows 7
  • Jackson.Burstyn Level 1 Level 1 (0 points)
    malku wrote:
    I have installed several times Windows 7 on my imac 27 with ATI Radeon HD 4050. I want to try what you did, downloaded the catalyst 10.4, but still don't know how to install manually 8.723.0.0 is't the one that comes with Catalyst 10.4 or do I have to roll back to another driver version like explained in other discussions?.
    Please help me, I need to get working with Autocad 2010.

    I've been waiting for the answer, Would you pls post it here? Thank you! Anybody can answer it?
  • Buhu Level 1 Level 1 (0 points)
    I was looking for this answer myself.
    After having now searched for hours I finally found the answer on another forum and I thought I would share it in here.

    Basically the solution is a new driver, but to be allowed to install a new driver we need to modify the .inf file first.

    This worked with my iMac 27" - Ati HD 4850:
    VERY step-by-step... sorry

    - Download the desired driver ( I use the driver from this post 8.723).
    - Start the very first install, it will unpack into the selected folder.
    - Then after it having unpacked, cancel the installation.

    - Locate the folder with the .Inf files ( eg. C:\ATI\Support\10-4vista64_win7_64_ddPackagesDriversDisplayW76AINF )
    - Open any of the 2 .inf files (doesn't matter which) in notepad.
    - Replace the lines which contains the name "ATI Radeon HD 4850"
    So that it equals = ati2mtag_R7X, PCI\VEN1002&DEV_944A&SUBSYS00B5106B
    Like so
    *"ATI Radeon HD 4850" = ati2mtag_R7X, PCI\VEN1002&DEV_944A&SUBSYS00B5106B*
    - Save the file.

    - Open device manager, selected the Ati-card, press update driver...
    Select "Locate and install driver software manually"
    Select "Let me pick from a list..."
    Select "Have disk..." and navigate to the folder with the modified .inf file.
    Choose "ATI Mobility Radeon HD 4850 Version whatever "
    It will warn you that the driver is unsafe - ignore this.
    If you are as lucky as I, your driver should now be installing...

    Hope this might help someone
    iMac 27" i7, Windows 7, Win7 64bit
  • mbatte Level 1 Level 1 (0 points)
    Just to confirm, when I install the ATI Catalyst package, it will only install and update the drivers and it does NOT install ATI Catalyst application. I remember for my PC I use to get an ATI icon at the bottom of the desktop that I could open up to check out the drivers, video card setting, etc. However, it seems that in Bootcamp, it does not allow it to install.

    Is that correct? or is is that the ATI Catalyst no longer installs this application, and is for the drivers only.
    iMac (Late 2009 - i7), Mac OS X (10.6.4)
  • Steven Richason Level 1 Level 1 (0 points)
    This same thing is happening with my MBP 17" Core Duo (Non-Unibody). All of these instructions/problems/drivers seem to be affecting people with iMacs... Anyone have this issue with a machine like mine? Obviously the drivers would be completely different...
    NonUnibody MBP 17" Core Duo, Mac OS X (10.6.5), 2gb ram
1 2 Previous Next


More Like This

  • Retrieving data ...

Bookmarked By (0)


  • This solved my question - 10 points
  • This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.