Installing Windows 7 on 24" iMac 6,1 (late 2006)

The 24" iMac (iMac6,1) from late 2006 has a problem when installing Windows 7 using Boot Camp. The greater part of the installation proceeds smoothly until the system gets to starting Windows for the first time. Many of these machines have the NVidia 7300 or 7600 GT graphics card but the Windows 7 supplied driver does not work well with them. Similar problems have occurred for folks with ATI graphics cards. As a result, a blue screen of death (BSOD) appears and causes the system to restart in a continuous cycle. Many solutions are described over the web. Some require installing Windows more than once.

This tip is similar to those posted elsewhere but it gets the job done in one go (well, almost).

1. Boot from the Windows disc to begin installation.

2. When the BSOD appears and causes a restart, hold down the ALT key.

3. Select the Windows disc to boot.

4. Press any key to boot from the disc when prompted to.

5. After selecting language preferences, click on Repair Computer and select the installation of Windows on your drive (c:)

6. In Advanced options, select Command Prompt (the last option in the list).

7. Depending on your graphics card, enter one of the following options at the prompt:

    a. NVIDIA card:
                del c:\Windows\System32\drivers\NVLDDMKM.sys

    b. ATI card:
                del c:\Windows\System32\drivers\ATI*.sys

8. Close the Command Prompt and click on Restart.

9. Let the system boot up from the hard drive this time. Since the video driver is no longer available, the installation should proceed as normal but on a low resolution.

10. Insert your Leopard/Snow Leopard disc and install the Boot Camp software.

11. While the software installs, download the latest video driver for your card from the NVIDIA website. Here is a direct link to the driver search page for the NVIDIA drivers.

The NVIDIA installer will not work until the system has been rebooted (due to Boot Camp). The steps that follow have been tested with a 24" iMac6,1 with the 7600 GT graphics card. Unfortunately, I have not tested how the ATI graphics card behaves after the Boot Camp install. If you know something about this, please leave a comment.

• Here's the tricky part. Boot Camp places the NVLDDMKM.sys driver back where you deleted it from. 
• After installation completes, you are asked to restart the computer. Doing so gets you back to the BSOD continuous boot cycle. You could repeat the steps above to get by this problem. But there's an easier way around this. 
• This is the most important step. DO NOT RESTART THE SYSTEM.

12. Launch Windows Explorer and navigate to the drivers folder located at:
        c: drive > Windows > System32 > drivers

13. Rename the NVLDDMKM.sys file to something else, like NVLDDMKM.old.

14. Restart your system. You wont see the BSOD this time because the problematic driver is not available (you renamed it in the previous step).

15. Once you've logged on, install the NVIDIA drivers you downloaded in step 11.

16. Restart again smoothly into Windows 7.

Other things to watch out for:
Windows Update may prompt you to install an "updated" driver for the 7300/7600GT cards. Using these drivers causes the same BSOD problem so avoid that update.

Hope this helps out some of you.

Tags: windows 7, imac, display driver