When I originally set up my Boot Camp partition I just picked a split of 50% for each drive – 256GB for OSX Mountain Lion and 256GB for Windows 8. After settling into Windows 8 and not really being very interested in OSX I wanted to allocate more space to the boot camp partition. I thought it would be simple and in the end it was, but the first things I tried didn’t work.
The following steps worked for me:
- In OSX shrink the ‘Macintosh HD’ volume using the native Disk Utility.
- Reboot into Windows 8, schedule a chkdsk /f and reboot.
- Using MiniTool Partition Wizard Home Edition 7.6 I extended the ‘bootcamp’ volume hosting Windows to use this new unallocated space freed up when shrinking the OSX volume.
I originally tried using the native Windows 8 disk management utility but it is not able to ‘extend’ the Windows volume. This didn’t work however because the free space is to the left of the volume, not the right. The use of this Partition Wizard tool gets around this as it is able to extend the volume to the left.
Previously I had tried CampTune but it didn’t work – I suspect it doesn’t support Windows 8 yet.
If you want to learn more about the OSX Disk Utility program I suggest reading this. And for a guide to some of the other techniques for resizing your Boot Camp partition I suggest reading this guide.
Loading tweets...
21 comments
Justin
October 10, 2012 at 4:18 am (UTC 10) Link to this comment
This worked like a charm for Windows 7/OSX Lion as well. Thank you very much for posting this. Every other site or write-up only leads to purchasing Camptune X or WinClone.
This was easy, fast, and free!
Wilson Cheng
October 12, 2012 at 1:47 pm (UTC 10) Link to this comment
This works like a charm!
I panicked a bit when I check the free space after the resize is only 1GB, and then i worked out it is the paging file growing bigger after the resize.
Daniel
November 1, 2012 at 11:03 pm (UTC 10) Link to this comment
Hi.
Alternatively, if I want to increase my Macintosh HD and decrease my bootcamp partition, do you think I can safely use the Windows 8 disk management to shrink my bootcamp, then use the Macintosh disk utility to recover the abandoned space for my Macintosh HD? I.e., exactly the opposite of what you did? Thanks
KK
November 2, 2012 at 1:35 am (UTC 10) Link to this comment
Hi Craig
Thanks a lot. This was much simpler to do than the other methods – such as using winclone. However, after doing this, I notice that when I boot to mac, I no longer see the bootcamp partition as mounted and also in DU, I still see the unallocated space. Must be because we expanded the bootcamp partition from within windows. Can you tell me how to fix this and get Mac to recognize the bootcamp partition again. I need this mainly to get bootcamp as my primary boot partition.
Russell
December 5, 2012 at 8:05 am (UTC 10) Link to this comment
KK, were you ever able to resolve this?
I too am experiencing the same issue. I can only see “disk0s4″ in my OS X Disk Utility and cannot mount it. Windows still boots just fine.
Josh
January 21, 2013 at 2:40 pm (UTC 10) Link to this comment
Unfortunately, I have the same exact issue when using. Thankfully I backed up everything prior to starting, that could have been a real bummer.
Looks like I’ll be using the bootcamp assistant to restore my drive to a single partition, reinstall windows 7, and restore my windows 7 data using the backup. In case you were wondering, this is the recommended procedure listed in the documentation provided with bootcamp by Apple.
I am curious why some of us have success using this method while others do not …
Daniel H
November 8, 2012 at 5:12 am (UTC 10) Link to this comment
Craig,
I have a MBPr and when I try to use the Disk Utility via the only method that allows partitioning (booted to recovery partition) it won’t let me unmount the Macintosh Disk to resize. Is there any easy way to make this work? There is no optical drive and I’m loathe to hack my way through creating a bootable USB drive to run disk utility off of that…
Any help is appreciated.
Firas
November 9, 2012 at 10:49 pm (UTC 10) Link to this comment
One problem i faced using your method and still trying to fix it:
The OSX did not recognize the the NTFS partition resizing. It fails to mount it and view it as it’s original size.
It is giving the error: invalid bs_jmp boot
Thanks
Adrian
January 2, 2013 at 2:04 pm (UTC 10) Link to this comment
Have you figured out how to resolve the bootcamp partition not being recognized error? It’s driving me crazy as I NEED a link between my windows and mac os x files! Thanks.
Amir H
November 16, 2012 at 7:13 pm (UTC 10) Link to this comment
Wow, I normally never reply to anything on the internet, but for once I have to.
I have now spent weeks on Google looking at a multitude of different ways of doing what you just showed us, by either completely deleting my BootCamp and creating a new partitition, to using WinClone and Paragon Camptune X, but none of those methods can come anywhere near what you just showed us.
Reading your post for 5 minutes, and performing all the steps, I have now increased my BootCamp partitition with over 80 GB! Thanks a lot!
Cheers
Russell
December 5, 2012 at 6:53 am (UTC 10) Link to this comment
Magical. Thank you SO much for writing this up. Saved me hours of reformatting/Boot Camp Assistant/reinstalling of Windows.
Tim
December 22, 2012 at 5:50 pm (UTC 10) Link to this comment
I never comment on blogs or websites, but just have to say a huge thank you for posting this. On Macbook Air and dual booting Windows 8, all other places I looked were telling me (unsuccessfully) to either use clone and restore or use gparted/paragon, none of which worked for me. It was so easy! Not sure how I avoided all the EFI/MBR hassles with re-partitioning but hey, it works.
Rich
December 28, 2012 at 7:06 am (UTC 10) Link to this comment
Thanks for the info. Unfortunately, I can’t get Disk Utility to work for me. I’m a PC guy, just switching to a new iMac. Running Mountain Lion and Windows 7. I’ve got partitions setup, but I want to shrink my OSX partition and enlarge the Windows partition. I’ve got Partition Magic setup in Windows and having used it before on my Windows machine I understand the concept.
My problem is, I can’t get Disk Utility to shrink my OSX partition. I see the partitions, but can’t get anything to work except the minus sign to eliminate the Bootcamp partition. What am I doing wrong?
What exact steps do I take to get Disk Utility to shrink the OSX partition. Thanks.
Aloha
Geoff
December 31, 2012 at 1:23 pm (UTC 10) Link to this comment
I wonder if this utility will work under the following circumstances:
- I currently have two partitions on my imac 1 tb disk, one for OSX Mountain Lion (200gb) , 1 for Windows 7 (800gb)
I’ve just purchased Windows 8 and want to evaluate it before wiping over Windows 7. Therefore I want to create a third partition by shrinking the existing windows 7 partition from 800 gb to 500 gb and creating a new 300 gb partition for Windows 8. So then I’ll install W8 on this partition and want to be able to boot into either W7, W8 or Mac OS X. Is this possible? I have tried using the Bootcamp utility in OSX but the only option it gives me is to unistall windows 7.
Anda
January 2, 2013 at 9:29 pm (UTC 10) Link to this comment
So good!! Thank you, master Obiwan
Everything else is just rubbish 
Rich
January 3, 2013 at 6:20 pm (UTC 10) Link to this comment
In my experience Disk Utility does not work with Mountain Lion and a Fushion Drive, other than to eliminate the Bootcamp Partition. I’m not sure which, or both, is the limiting factor. When I click on the OSX partition no further action is allowed. The partition is outlined in blue, but it will not adjust. I can also highlight the small window showing the size of the OSX partition. I can not, however, change anything.
FYI, I’ve tried StellarPartition Manager. Do NOT go there. After days of emailing back and forth to India, communicating with people who don’t seem to know much about the software, I finally asked them to ‘kick it upstairs’, not in those words. Someone got back to me and we established a link so that they could look on my computer. The result is, they say my HDD is encrypted. That’s why their software doesn’t work. Never mind that the earlier version Trial software shows my Bootcamp partition and said it would partition the HD. The version I PAID for does not show the Bootcamp partition and does not work. Stay away for them.
Also Camptune does not work with Mountain Lion.
My next step is iPartition. The trial software shows all and indicates it will partition everything. They even say they will adjust the Bootcamp partition. Hmmm…..have I heard this before? Will advise. Aloha
Rich
January 6, 2013 at 9:21 am (UTC 10) Link to this comment
Ah well, I contacted Apple support for their input. Uh, eliminate the Bootcamp partition and start over.
I also contacted iPartition before I bought the program and even though the trial software showed all my partitions including Bootcamp, they said their software would NOT change my partitions.
iPartition tech support when asked if their software would work on my Fushion drive, stated,
No, it won’t, I’m afraid. The reason it said that (why the other software said my HD was encrypted) is because the technology underlying the Fusion drive is the same as that used by FileVault 2. Apple haven’t made the necessary information publicly available.
So, there you have it. I just blew up my Bootcamp partition and redid it. It took three times to get Windows 7 to install correctly, but it’s done. I wish I had better news. I am interested if anyone else has another way.
Michael
January 10, 2013 at 5:26 am (UTC 10) Link to this comment
This will turn into disaster if you use BOOTCAMP because the partition won’t mount it (and parallels can’t run on a bootcamp partition)
Other than that it for fine
stuartbell
January 21, 2013 at 5:29 pm (UTC 10) Link to this comment
There might be some issues with bootcamp while creating or deleting a Windows partition. And the parallels my not identify the partitions.
In my case, it was little different because I create new partition, not for Windows but, to save my different types of data separately. The tool I went with is Stellar Partition Manger.
Jeff
February 17, 2013 at 3:45 pm (UTC 10) Link to this comment
Worked great! Thanks a bunch.
Jackie
April 15, 2013 at 5:57 am (UTC 10) Link to this comment
Thank you so much for this. I recommend this for anyone who wants to repartition their drive and not lose any data.