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Resizing Windows Bootcamp Partition on my Macbook Pro

Finally got an update for my site! (I need to work on more, we’ll see). Useful information to post which I need to record mostly for myself if I ever do this again!

Basically resizing partitions can take a while; mainly due to moving data. My situation was that my Windows 7 partition was too small; I was down to 1GB of space (150GB was Windows, 600GB was Mac OSX on a 750GB drive). This likely, doing somewhat in reverse, could

In preparation I made a backup; not that I had much to backup. :) You may also want to defrag the drive fully (moving all data to the front) so it is slightly faster to extend; I’d recommend JkDefrag:

Resizing Mac OSX partition

The first step was to resize the Mac OSX volume. This first required me to decrypt it; takes a while but after that the Disk Utility can easily resize HFS+ volumes. Simply find it in the Utilities folder, open it up, select your drive and click on the Mac OSX partition to resize it. Some oddities arose; I now can see the “Recovery HD” partition when I hold down Alt (the “Option” key) on bootup, so it moved that to the end of the partition. Who knows where it was before.

Resizing Windows partition

The second step is to resize Windows. I did this with one note, which I am not sure is entirely true but whatever; I left a 10MB space (apparently needs to be at least 512KB of space) between the last part of the Mac OSX drive and the Windows drive I was extending.

The tool of choice was GParted; – just booted by holding Alt as normal. I changed the preceeding space to 10MB, and made sure it went to the end of the drive.

Another thing to note is that it said I had to do a checkdisk of my Windows partition. I did a full checkdisk – rebooted into Windows, right clicked the (C:) volume and chose Properties, selected Error-checking “Check now…” button under “Tools” and selected both checkboxes (essentially choosing /f and /r). Of course you can’t do it when it is loaded so after restarting it did the checks and I was ready to resize.

Problem: Windows is no longer seen!

Once Windows 7’s partition was resized came in the problems; the default bootloader (holding down Alt on boot) didn’t see the “Windows” partition anymore. I used 2 things to fix this.

The first was rEFIt; – this replaces the Mac OSX bootloader and has a nifty tool built in that I had to use – install it in Mac OSX using the DMG download. The problem with resizing Windows is that Mac OSX’s bootloader no longer knows where the Windows partition starts – there are essentially two layouts for the drive (GPT and MFT), which are now out of sync due to GParted increasing the Windows size. Once installed I restarted and used the Partitioning Tool, which automatically detected the error and asked to correct it. Once corrected Windows then was known to rEFIt properly; after a few reboots for me at least.

Final Fix: Inaccessible Partition Error

Last thing was that Windows itself now was bothered by the resize; generally this will also happen if you, say, had 2 Windows installs on a machine, deleted the one at the front of the drive and resized the latter to fill the drive. Windows thinks that the files to load the OS are located in a very specific place on the drive, which would now be wrong.

It comes up as black screen error; if that doesn’t occur, great I guess :)

If it does, it requires either something like ERD Commander (known now as MS DaRT); I used version 6.5, but the same process is achieved through using a bootable Windows installation or upgrade disk; the Repair option will search automatically for such basic issues with a current installation and ask to apply fixes. Do so and it should allow full access to your Windows partition again :)

Again the CD was just booted through using Alt/Option key on bootup.

You could now remove rEFIt, I may well do so in case I want to re-encrypt my Mac OSX partition, since it likely would interfere (and most certainly is unsupported according to its own documentation).

Hope this helps someone else; certainly when I searched Google it took a fair few threads and posts to find all of this, since most of them point to (now) paid tools.

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