Mac can't see WIN7 installation after removing drive with XP installation

[jevonM]

I have a Mac Pro (early 2008) with 4 internal drives. About a year ago I did a BC installation of Windows XP Pro on one drive, and recently I did a BC installation of WIN7-64 on another drive. The drives are:

Bay1: 1 partition: SL (Mac OS Extended Journaled)
Bay2: 2 partitions: WIN7-64 (NTFS) / SL backup (Mac OS Extended Journaled)
Bay3: 1 partition: Data (NTFS)
Bay4: 2 partitions: WIN-XP (NTFS) / Data (Mac OS Extended Journaled)

This may or may not be important, but NTFS-3G is active in my Snow Leopard installation.

When I want to boot into Windows I hold the option key down and am presented with:

Snow Leopard Snow Leopard Backup Windows

I select Windows and am then presented with a DOS-like screen giving me the choice of booting into Windows 7 or "Earlier version of Windows". All fine, and I can elect to boot into either WIN-XP or WIN7.

I bought Acronis True Image Home 2011 and the Plus Pak (to handle GUID partitions) and a 2T drive to use to back-up the 2 Windows partitions

I removed the drive holding data only from Bay3 and inserted and partitioned the new 2T drive as follows:

1-HFS Journaled
2-NTFS (to hold the Windows backups)

I then used Acronis to individually back up the WIN7-64 and and WIN-XP partitions to the NTFS partition on the 2T drive. That all went fine.

I obviously want the 2T backup drive available all the time to do backups. Since I don't use WIN-XP much anymore, and I also need the data on the drive that was in Bay3 to be available, I removed the drive with the WIN-XP partition (Bay4), moved the 2T drive into Bay4. Then I put the data drive back into Bay3.

Here's the problem: Now, when I reboot the Mac and hold down the Option key to select Windows, it no longer appears as an option. Only my two SL installations are presented. Ditto with the Startup Drive function in System Preferences.

On a hunch, I removed the new backup drive from Bay4, put the drive with WIN-XP back into Bay4, and everything works as before.

So it seems to me that there is something on the WIN-XP drive that enables the Mac to see the WIN-XP partition and the WIN7-64 partitions as bootable. Remove the disk containing WIN-XP and the Mac can't see the WIN7-64 installation either.

Is there a fix for this?

Thanks.

Jev McKee

 

[jevonM]

OK, I've pretty much figured out by now that on my system the MBR is located on the drive with XP-Pro. See image from the Disk Management tool below (the Windows 7 drive is labeled "BOOTCAMP"). So the Mac cannot see the Windows 7 installation unless the drive with XP is in the bay.

Booting the Mac from the Windows 7 Install disc and using the repair function does nothing, probably because the repair tool sees a valid MBR on the XP disk. If I boot the install disc repair tool without the XP drive in the bay the repair tool can't even see the Windows 7 installation. So I'm SOL with that possibility.

Apparently this is not an uncommon problem. I Googled "mbr wrong disk" and got quite a few hits. Among them was this one explaining how to use bcdboot from the command line to copy the MBR from its existing location to the drive you want it to be on.

I think I understand how to enter the command to copy the MBR to my WIN7 installation. What I don't understand is where the author says:

"I ran it, and rebooted. I immediately went into the BIOS and changed the Boot Order so that my 300 GIG C: faster drive (the one I thought I was booting off of all the time) was my startup drive."

Do I need to perform this step? I think this probably not necessary for my situation, but please correct me if I'm wrong.

Also, two more questions:

-What's your best guess about whether doing this will allow the Mac to see the WIN7 installation as bootable?

-Will bcdboot also remove the MBR from the XP installation so I'm not dealing with dueling MBRs when both Windows disks are in the computer at the same time?

Thanks again.

- Jev McKee

 

[DeltaMac]

Your MacPro doesn't have a BIOS, so you can't try changing the Boot Order in the BIOS, even if you wanted to.

My guess is that utility that will copy the MBR to your Win7 disk will be a good chance.
I don't know about an issue with 'dueling MBRs'...
But, it does sound exciting, Let us know how it goes...

 

[jevonM]

I tried bcdboot but couldn't get it to work. Following another user's suggestion I tried the additional step of using the Windows 7 Disk Management tool to set the partition status to Active. This didn't resolve the issue either. Running bcdboot again after this step had no result.

Someone else suggested I check out EasyBCD, and this worked! On the "BCD Backup/Repair" tab you simply select "Change boot drive," then hit the "Perform Action" button. At the pop-up menu presented you then select the partition you want to boot from. It's really that simple. The procedure creates the required files on your selected Windows installation, and assigns the "System" and "Active" flags to it.

After this I could remove the disk with XP and the "Windows" selection appeared when holding the Option key at boot. The Windows 7 installation also shows up fine when booting from the WIN7 Installation disc.

I had one small problem still with the Windows 7 partition not appearing in the Mac Startup Disk System Preference pane. This was a nut-buster to figure out. On a hunch I disabled NTFS-3G for that volume, and everything now works as expected.

@DeltaMac: yes, the bios thing is not necessary on Mac. The Startup Disk System Preference pane is the equivalent, I guess.

Thanks.

- Jev McKee