Windows 7 on 27" iMac : Black Screen - Mac-Forums.com

Ragna · 11-05-2009, 09:40 PM

Hello!

After several enlightening hours spent exploring the forum, I didn't find a solution to my problem, so let's start a new topic explaining my situation :

I've had a 20" iMac for 2 years with a Dual Boot Mac OS X / Windows XP, and was very happy with it.
I bought a few days ago the new 27" iMac as I couldn't resist the huge beautiful screen. But I still need Windows for several activities. So I thought about installing Windows 7.
Being a student, I took advantage of this offer : Microsoft Student - Windows 7 .

Problem : It doesn't gives an install disk, but only a download of an update that allows to "upgrade" Windows XP or Vista to Windows 7.
So it seemed to me I had no choice but to install Win XP or Vista with Bootcamp, and then upgrade it to Windows 7.

I have legal versions of Windows XP, so I installed it on the iMac with Bootcamp. All went fine. Then I downloaded the upgrade, and the upgrade assistant to Windows 7, with no worries. But when I started the Windows 7 install, the following happened : The first steps went fine (Copy of Windows files, Decompression of Windows files, Install of fonctions, Install of updates), but at the last step called End of install, I just had a black screen.

I let it run for a while, nothing happened. So I rebooted, and after the Windows logo I had a black screen again.

I cannot start the safe mode with F8 because the install has not been completed. And still with F8, starting in a low resolution doesn't help.

So at this point I'm a little lost, and would be very grateful of any idea that could help making things advance. Thanks

Kash · 11-05-2009, 10:30 PM

My brother had the exact same problem with his 27" iMac. After doing a bit of searching, here is the solution to your problem

One change, in step 6, replace NVLDDMKM.SYS with ATIKMDAG.SYS

Ragna · 11-06-2009, 09:37 AM

Thanks! I did some reasearch too, and came across this topic : Apple - Support - Discussions - Black/Blank Screen with Boot Camp Win 7 ... where one person links to the same site you do.

So now the install went fine, and I've also installed Bootcamp 3.0.

The only problem now, was that I couldn't go higher than a 1920x1440 resolution.
As one person in the thread I linked said : "The BootCamp driver that loads only give a max resolution of 1980 X 1440 so everything looks stretched. Installing the ATI drivers from ATI did no good."

But the next one says "After following your solution and then run the window 7 update, the screen rsolution issue is now resolved. I think Microsoft just released an update sometimes today and the update is reading as following:

"ATI Technologies Inc driver update for ATI Mobility Radeon HD 4670". "

And indeed after this update it works perfectly.

Edit : Also, there was no sound, but Windows found the problem all by itself, downloaded some driver and it worked instantly after that. I have to say this Windows 7 looks very good so far, and it seems it'll be a pleasure to use when I have to leave Mac OS

chscag · 11-06-2009, 03:42 PM

Thanks to you and Kash for the great info! I hope other folks will refer to this thread to help resolve the same or similar problems. I've got this thread bookmarked.

Regards.

todd51 · 11-14-2009, 12:29 PM

I'm having the same problem on my new 27" iMac. I have a question for you Ragna, how did you boot from the Win7 disc if you did the download from the upgrade site? Did you just use your XP disc to delete the file? I also downloaded the upgrade so I don't have a Win7 disc to boot from.

todd51 · 11-14-2009, 01:01 PM

Woo Hoo! I got it! For anyone else with this issue (I'm sure there will be more people in the near future) I couldn't even boot from the XP disc because I couldn't get past the Administrator Password in the Recovery console. So, I downloaded the free trial of Tuxera so that I could get write access to my Bootcamp partition in OS X. Restarted my iMac and navigated to C

Windows\System32\drivers and deleted the ATIKMDAG.SYS file, then removed it from the Trash, rebooted to my Windows partition and now I'm continuing with the Setup!

Man this was a headache.

Kash · 11-14-2009, 07:26 PM

Tell me about it, I had to troubleshoot for my brother who lives on the other side of the country so I didn't even have access to the physical machine.

scottamoulton · Yesterday, 12:53 AM

Ok, so I got it to work out of the box. Here is what seems to be happening. When the screen goes black, it is the second monitor that becomes active leaving the primary 27" mac screen black. If you continue the installation on the second screen, when it is done it switches back to the Mac 27" as the primary screen.

I noticed this because I hooked up a secondary screen during the install. After that the rest of the install worked (oh I also hooked up wired keyboard and mouse), including having 2560x1440 resolution.

After the install was done, the only thing that did not work (although the system says it does work) is sound and bluetooth. After the system did its own update the Bluetooth started working, both the mouse and keyboard, the ATI drive got updated on its own, and then sound started to work all by itself too. The funny thing is the sound that started to work seems to be over the HDMI connector to the second monitor. But at least I did not have issues making me delete any files.

So you guys, just hook up second monitor on the Display Port, a Mouse and Keyboard, install, do the updates, and it all works perfect.