MXM Error Using Windows

Hi, I installed Windows XP Professional on my iMac 24 using Boot Camp (which has the NVIDIA GeForce 8800 GS video card installed, plus 4 GB of RAM) but whenever I try to boot using Windows I get this message:

ERROR: MXM Structure not found or invalid.

Reflash MXM ROM or add MXM structure and associated callbacks to SBIOS! Post will be halted to 30 seconds and performance will be limited to balanced performance mode until this is resolved...(and then counts down from 30 to 0 and boots Windows.)

I am having a really hard time trying to find out how to fix this problem. Is there any help at all you could give me in resolving this issue? I (and the others who are having the same issue) would greatly appreciate it.

Mac OS X (10.5.2), iMac 24

Posted on May 24, 2008 3:03 PM

24 replies

Jun 15, 2008 11:10 AM in response to VegasCrook

Alright everyone, I believe I've found our only options. According to the Apple expert support fellow, there are only two ways to fix the MXM error:

1. Download and run the MXM 1.0 Update found at this link: www.apple.com/support/downloads/imacmxmupdate10.html

2. If that doesn't work (which is apparently quite likely), then the final and sure fix is to take your iMac to an Apple Authorized Service Provider (to find one in your area, call 1-800-263-3394) and have them replace the NVIDIA 8800 GS video card.

End of problem. Thanks so much to all who joined in this quest, and God bless.

Jun 15, 2008 1:15 PM in response to swordswinger710

Thanks for the information but the real question is:

would the authorized dealer replace the card on "his" account, apple's account or mine???

Thanks in advance.

Jun 17, 2008 11:19 PM in response to swordswinger710

Update: Apple Support gave me this info today:
1. The Apple engineering team have been able to reproduce the mxm error;
2. The mxm fix will be developed by Apple (I have no idea about due date sorry);
3. The fix will most likely require a firmware update;

Jun 22, 2008 2:33 PM in response to protoGamer

Bought yesterday and feeling sad today. We're having the same MXM error problem trying to get XP installed. Tech support agreed with statements above -- so back to the apple store we go.....

I am wondering though....how can we check out the replacement computer to make sure that the problem isn't there, too? How frequently is this happening? Any ideas? Estimates? 1 in 10 1 in 100 1 in 1000?

Your thoughts, please.....

Jun 30, 2008 10:02 PM in response to disappointed one....

I mentioned my MXM error to the techs at my local Apple store. They escalated my issue to Apple and I got a phone call today stating my logic board needed to be replaced. They stated this was the only way to resolve the issue.

This is my first Mac (I'm a converted IT Professional) and so far I'm not very impressed...

Aug 5, 2008 3:19 PM in response to BBDMontreal

The authorized dealer should replace the card on apple's account.

Aug 8, 2008 4:53 AM in response to Dust-iMac

Any word on the date for the MXM fix? My organization purchased 6 new iMacs, all with the 2.8 processor. Five have the ATI card. We upgraded to the NVidia card on one machine. Guess which one has the problem? The upgraded version, of course. Frustrating. The ATIs work fine.

Aug 20, 2008 3:10 PM in response to Candiness

I have a follow-up note. My organization received a prompt response from Apple regarding our malfunctioning machine. First, they asked us to wipe the hard drive and reinstall everything. We did so. Unfortunately, the same MXM error message returned.

So Apple gave us a choice: have the NVidia gpu replaced or swap our machine for a new one while Apple's engineers tear apart the old one. They actually said that they preferred to give us a new machine so that they could investigate the malfunctioning Mac. That speaks well of their approach, and it's clear that they are "on the case."

We just received our new machine today (also with an NVidia 8800) and we were able to install Windows without a hitch. So far so good.

drmatto

Level 1

0 points

Sep 24, 2008 7:00 PM in response to swordswinger710

I get the same problem, have been waiting for a solution, nothing.

Also, my duel monitor set up fails to work in Vista (bootcamp) when i boot into it. Only one monitor will work. This seems to be the balanced performance mode?

Have tried everything.

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MXM Error Using Windows