Deleting Windows Partition From Boot Camp Makes It So I Can’t Boot Up MacOS

Question

Level 1

4 points

Deleting Windows Partition From Boot Camp Makes It So I Can’t Boot Up MacOS

Hi! Every time I have gone to delete/repartition (I can’t remember the exact word) the windows partition through Bootcamp, it makes it so my MacOS can’t log back in (ex. After putting in password it glitches out and then returns to login screen)

I know how to fix it- I have to open my computer in recovery mode and re download macOS Sonoma. But this feels highly impractical and high risk.

is there anyway to prevent this from happening? How can I safely delete a partition without risking it messing everything on my Mac side up?

I assume that Bootcamp is just accidentally deleting whatever Mac uses to boot up as well.

MacBook Pro 16″, macOS 14.8

Posted on Oct 3, 2025 5:55 PM

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Answer 1

Oct 3, 2025 5:58 PM in response to sj136

You must use Boot Camp Assistant to remove Windows and the Boot Camp partition.

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Answer 2

jessevas

Level 1

14 points

Oct 10, 2025 12:01 AM in response to sj136

I hope you have a recent backup of your Mac's drive because I suspect you're going to need it,

You'll probably need a bootable USB stick with a macOS installer on it; you would boot up the USB stick, and instead of proceeding to install, you would select the recovery options to try to repair the drive (first step would be to use Disk Utility to attempt to repair the drive's partition map and then the partitions themselves); if you don't have such a stick, you'll need to create one using another Mac.

To actually boot the USB stick, power up the machine with the stick plugged in and keep the option key held down until the machine offers a choice of bootable drives.

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Answer 3

zbookvc

Level 1

8 points

Oct 13, 2025 5:46 AM in response to sj136

Using the Startup Disk Converter application in macOS to remove the Windows partition is the only safe method for rebuilding the boot record.

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