Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I just resized my Windows 7 NTFS partition on my macbook using GParted. Now, when I hold down the option key at startup, this partition doesn't show up. My OS X partition shows up normally. So I can't boot into the Windows 7 partition. This partition does show up in Finder and I can access the data on it. I believe there is something wrong with the EFI bootloader or the GUID partition table. However, I'm not sure exactly what the difference is between the two. Is there a way to modify these to make my MB startup in Windows 7 again? Thanks for the help.

share|improve this question
up vote 2 down vote accepted

In this case, my first suggestion would be to back up the partition, and recreate it via bootcamp. I don't see another way to recreate the disk partition properly.

You could try repairing it with Winclone, but I am not sure of the Windows 7 support status of Winclone... And Apple hasn't officially released a version of bootcamp that supports Windows 7 yet... (eg, no Win 7 drivers).

The issue is certainly that the GUID and/or EFI Bootloader are "injured".... You could always try booting from Windows 7 DVD, and asking it to repair the installation. I have seen that do some wonders...

share|improve this answer
Thanks for the suggestions. How do you repair it with Winclone? Isn't this program just a disk imager? I don't see a repair option in this program. Thanks – themacfreak Dec 28 '09 at 16:42
Of the top of my head, I am not sure that Winclone will solve the issue.. But try resizing the Bootcamp partition with Winclone.... That should force it to rebuild the necessary structures... Assuming that feature is still there... – Benjamin Schollnick Dec 28 '09 at 20:37

I had the same problem when working with my Windows partition, it wouldn't boot. I found using rEFIt to sync the GPT and MBR maps and then using the Win 7 startup repair options fixed it for me. Posted about it here:

share|improve this answer
Welcome to Super User... We would like if posters copy the gist of the information offered on websites, in case sites go down without warning – Canadian Luke May 23 '12 at 7:10

Are you able to select Windows as the boot partition using System Preferences?

You might also see if running Disk Utility on it will reset any boot options.

share|improve this answer
If the Bios level boot screen doesn't show it, then System Preferences might show it, but it won't be able to boot. – Benjamin Schollnick Dec 28 '09 at 10:45
Yes, the Windows partition shows up in system preferences but when I choose it and restart the computer, the mac just stays on the gray screen you see at startup. Disk utility does not allow me to verify/repair the windows partition. Thanks for the suggestions – themacfreak Dec 28 '09 at 16:41

You must log in to answer this question.

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