On Macbook Air, I have OSX 10.9.4 and it allows me to update to Yosemite, will this affect the Windows 7 partition that I installed using Bootcamp ?

Edit: seems to work ok for one windows/bootcamp partition, but an additional windows partition will cause problems. I will add a detailed answer to my own question.

3 Answers 3


Unless something goes wrong during install: no. But it's always smart to have a backup.

  • I edited my question, after update windows sees my second Fat32 partition as "unpartitioned space", Mac sees it OK as "Fat32" and can browse files.
    – adrianTNT
    Mar 9, 2015 at 15:36
  • So you have 3 partitions in total? 1 Mac 2 Windows? Mar 10, 2015 at 10:17
  • Yes, I had 1 Mac System, one NTFS with Windows system and one Fat32 as larger storage for windows. I don't remember how I created that setup, and I cannot do it again (still trying). I think the Yosemite update would have gone OK if I only had one windows partition.
    – adrianTNT
    Mar 11, 2015 at 14:45
  • Yeah, I guess bootcamp is not a fan of more than 2 partitions. Have you tried using disk utility to delete and re-add the 3rd partition? Mar 11, 2015 at 18:24
  • After re-initiating a bootcamp partition and re-installing windows around 5-6 times, I managed to do it with "MiniTool" partitioning software (as bootable stick). Yosemite update created 4 partitions: one very small with some booting data, one Mac, one Mac recovery tools, and one Windows/bootcamp. With MiniTool I was able to create a second windows partition after deleting the Mac recovery partition, because MBR has room for only 4. I let the bootcamp starting point untouched and a 600MB unused space in the middle of the drive (where Mac recovery was).
    – adrianTNT
    Mar 12, 2015 at 19:20

Updating from OS X to Yosemite on Macbook air seems to work OK if you have one Mac partition and one Windows/Bootcamp partition. But ...

If you have two windows partitions then the update will cause problems, the new partition setup created by Yosemite update was:

  • One very small partition (~ < 200MB), probably booting data
  • One Mac partition
  • One Mac recovery tools partition (~600MB)
  • One Bootcamp/windows partition

The MBR has space for 4 partitions (?!); so if you had two windows partitions, the second one (Fat32) might not be visible. In my case Mac could still see it and browse files, but windows 7 seen it as unpartitioned space.

I booted with an USB stick (Minitool Partition wizard free), deleted Mac "recovery" partition (to make room on MBR), created that 2nd windows partition from scratch. Did that without changing starting point of Bootcamp partition, otherwise windows might not boot.

You are losing the ability to boot into Mac recovery tools. But in worst case scenario you can delete all partitions and boot from network to re-install Mac from scratch.

I couldn't find a better solution to have two Windows partitions, tried re-installing and re-partitioning around 6 times, windows would fail to boot whenever I touched the bootcamp partition.

The tool should also work to re-size the bootcamp patition, as long as starting point remains unchanged.


I just upgraded from Snow Leopard to Yosemite 10.10.5 2 days ago. The upgrade took all evening. However, when I went to restart the computer, Yosemite was installed and my Boot Camp was there with Windows XP working just fine.

  • You had just one windows partition, correct? I think it only has trouble if you have two.
    – adrianTNT
    Aug 20, 2015 at 20:00

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .