Can't boot to Windows installed on the second drive in MacBook Pro

I have a mid-2012 15" non-retina MacBook Pro with Mountain Lion. I have a 256 GB SSD in place of the original drive and an OptiBay in place of the optical drive where I put the original 500 GB Toshiba drive.

On the SSD I have OS X. I want to be able to boot into Windows 7 on the second drive but I also want to have half of the space sacrificed for my additional data.

First, I created a HFS+ single partition covering the whole second drive. Then I opened Boot Camp Assistant and ordered it to split the drive in half - it put a FAT32 drive as the second one, there is no other option.

Then, I created a bootable USB pendrive using Bootcamp. Because the Windows installer it didn't allow me to install Windows on the second drive, I opened my laptop and disconnected the SSD. Then I installed Windows without any hassle, updated it, installed applications, rebooted a few times - it all worked.

Afterwards, I reconnected the main drive. Now OS X boots fine but once I choose Windows from the list I get an "No bootable device" error. I suspected it's an MBR issue so I booted again from the Windows image on the pendrive and I tried to enter the "Fix my computer" menu item to go to the console and run fixmbr but it tells me I cannot run this option since my installed Windows version doesn't match one on the pendrive (?!).

As a last effort I listed all my partitions:

$ diskutil list
/dev/disk0
  #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *256.1 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:          Apple_CoreStorage                         255.2 GB   disk0s2
   3:                 Apple_Boot Boot OS X               650.0 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk1
   1:                        EFI                         209.7 MB   disk1s1
   2:                  Apple_HFS OptiBay                 249.0 GB   disk1s2
   3:       Microsoft Basic Data Windows7                250.8 GB   disk1s3
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS OSX                    *254.9 GB   disk2
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *32.0 GB    disk3
   1:                 DOS_FAT_32 RALLY32GB               32.0 GB    disk3s1

(the 32GB-drive is the USB pendrive on which Bootcamp put its adjusted Windows installation image) and run:

$ sudo fdisk -u /dev/disk1
fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory

    -----------------------------------------------------
    ------ ATTENTION - UPDATING MASTER BOOT RECORD ------
    -----------------------------------------------------

Do you wish to write new MBR? [n] y

after a reboot I see a little changed disk order:

$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *256.1 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:          Apple_CoreStorage                         255.2 GB   disk0s2
   3:                 Apple_Boot Boot OS X               650.0 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS OSX                    *254.9 GB   disk1
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk2
   1:                        EFI                         209.7 MB   disk2s1
   2:       Microsoft Basic Data Windows7                250.8 GB   disk2s2
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *32.0 GB    disk3
   1:                 DOS_FAT_32 RALLY32GB               32.0 GB    disk3s1

but, unfortunately, the Windows option from the MacBook Pro boot menu is gone. :(

I honestly have no idea where to go with this from here... I'd be grateful for any help.


Install chameleon boot loader.

With this you can dual boot into windows or mac.

I have been using this since 2 years.


When you install Windows you should format the FAT32 partition before installing. From the Bootcamp installation guide:

2 When you’re asked where to install Windows, select the partition named “BOOTCAMP.”
NOTICE:  Do not create or delete a partition, or select any other partition. Doing so may delete the entire contents of your Mac OS X partition.

3 Click “Drive options (advanced).”

4 Click Format, and then click OK.

5 Click Next. The installer formats the Windows partition using the NTFS file system.