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

[first-born]

I am using the iMac that is one month old. Windows 7 was running without any issue for about two weeks and after that I found that the desktop screen get froze and pixilated. It shows me a message in the notification bar that “ATI driver quit but was recovered”. After that the entire screen went blank and it gets restored by itself. After sometime this happens again. I have not seen anything like this before and therefore I don’t have any idea about this. Is there anyone who knows that how can I solve the issue or what are the reasons behind that then please post that over here? This will be really helpful to me and other users who are seeking for the similar solution.

[Devasis]

This problem is well known with the iMac 27 (late 2009). I found many threads for this problem. You can do the following to let this issue off.

• First of all install Windows 7. Many people get stuck at this point because The Windows installer is not having the compatible driver for the ATI Radeon HD 4850 graphic card.
• After that install the bootcamp drivers that must be came with the snow leopard. Put the install disk of the snow leopard min and autorun will find the setup.exe.
• Once you are done with this then you have to install bootcamp drivers version 3.1.
• After that you have to go to control panel > system, device manager > display adapters. Find the 'ATI Radeon HD4850’ and double click on that.

[Solomon]

I am also having the same problem with my laptop. In my case the Win7 is working fine with under VMWare Fusion and I want any other option to run Win7 natively. For that I simply removed the Boot Camp Win7 from my computer and ran the Win7 as a virtual machine. I found that the simulated 27" monitor driver works without any problem in fusion. If we talk about the graphic performance then I can say that it gives the satisfactory result but it is not as good as native. I think that it will be only resolved when Apple and ATI ultimately obtain the Win7 Boot Camp drivers functioning.

[MrChris-]

I think that I have the solution for this. I found that my actual "modded" ATI Mobility RD4850HD is working without any problem with the Windows 7 Professional x64. Actually I am using the old 8.671 version. I was not able to adjust the new Catalyst 10.2 driver. I got an error that says "corrupted INF". Anyway, that is working properly now. I am not getting any display freeze or any pixilation on the screen.

[Calvin K]

There may be the problem with the display driver that is installed in your computer. That may be corrupted or not working properly and that is why you are getting such issues. Just uninstall the display driver and install that again to see whether it works or not. If that solves the issue then it is fine and if that is not working then you should download the latest driver available on internet and install that to your computer. Many of the time I have seen that reinstalling the drives solves such cases. You should also give it a try and I wish that will work for you also.

[ApPy10]

Microsoft has the best driver for the bootcamp Windows 7 iMac. You should search for the "Microsoft Update Catalog" on internet. Enter the catalog for the update and search for the “ATI Mobility 4850”. This will pop up two drivers. One is for 32 bit and other one is for 64 bits. Download one according to your computer and install that. Once you installed that then Windows Update will consider it as the newer version. You have to choose the hide for that optional update. To do that you have to go to control panel and right click on the driver and select hide it. This may help you.

[Team Leader]

I solved this problem in the following way: I downloaded the Catalyst 10.4 from ATI website. After that I installed the ATI Mobility Radeon HD 4850 display driver manually which was the version 8.723.0.0. This has 32 bit color and therefore it does not show the color banding or .any such issues. Autodesk do not support the ATI HD 4850 officially but I can run the REVIT 2011 with hardware acceleration and also anti-aliasing without any problem. I found that the performance of my computer is well improved without running any speed benchmarks. Hope this will help you.