Reset Windows 10 Local Admin Password on Mac

If you’ve forgotten the password for a local administrator account on a Windows 10 PC and only have a Mac available, you can still reset it without reinstalling Windows. This guide walks you through creating a bootable USB drive with a password reset tool, booting the PC from it, and clearing the password—no Windows login required.

What You’ll Need

• A Mac running macOS (any recent version).
• A USB flash drive (at least 1 GB, but 2 GB or larger is safer). All data on it will be erased.
• Access to the internet to download a password reset ISO file (e.g., from the official Lazesoft Recovery Suite or PCUnlocker website).
• Knowledge of the PC’s boot menu key (commonly F12, F2, Esc, or Del) or access to its BIOS/UEFI settings.

Step-by-Step

1. Download a password reset ISO. On your Mac, go to the official website of a trusted tool like Lazesoft Recovery Suite Home Edition (free) or PCUnlocker. Download the ISO file (usually named something like LazesoftRecoverySuiteHome.iso).
2. Insert the USB drive into your Mac. It will appear on the desktop or in Finder.
3. Open Disk Utility. Go to Applications > Utilities > Disk Utility. Select the USB drive in the sidebar (not the volume under it), click Erase, set Format to MS-DOS (FAT) and Scheme to Master Boot Record, then click Erase. This wipes the drive.
4. Open Terminal. Go to Applications > Utilities &em; Terminal.
5. Convert the ISO to IMG format. In Terminal, type: hdiutil convert /path/to/downloaded.iso -format UDRW -o /tmp/windows_reset.img (replace the path with the actual file location). This creates an IMG file that can be written directly to the USB drive.
6. Identify the USB drive. Type diskutil list and find your USB drive’s identifier (e.g., /dev/disk2). Be careful—this is the whole disk, not a partition like /dev/disk2s1.
7. Unmount the drive. Type diskutil unmountDisk /dev/diskX (replace X with the correct number).
8. Write the IMG to the USB drive. Type sudo dd if=/tmp/windows_reset.img of=/dev/rdiskX bs=1m (note the r before disk for raw mode). Enter your Mac password when prompted. This step can take a few minutes; wait until it completes.
9. Eject the USB drive. Type diskutil eject /dev/diskX and remove it from the Mac.
10. Insert the USB into the Windows PC. Plug it into a USB port on the locked machine.
11. Boot from the USB. Turn on the PC and press the boot menu key (often F12, F2, Esc, or Del) repeatedly as it starts. Select the USB drive from the boot menu. If it doesn’t appear, you may need to enter BIOS/UEFI and change the boot order or disable Secure Boot temporarily.
12. Run the password reset tool. The tool will load (this can take a minute). Choose the option to reset or remove a Windows password. Select the Windows installation and the local admin account you need to access.
13. Clear the password. Follow the on-screen prompts to set a new password or remove the existing one. Confirm the action and exit the tool.
14. Reboot the PC. Remove the USB drive and restart normally. You should now be able to log in with the new password (or no password if you removed it).

Common Mistakes

• Writing to the wrong disk. Using diskutil list and selecting the wrong identifier can overwrite your Mac’s internal drive. Double-check the size and name before running dd.
• Using the partition instead of the whole disk. You must write to /dev/rdiskX (the whole disk), not /dev/rdiskXs1 (a partition).
• Forgetting to unmount. If you skip diskutil unmountDisk, dd will fail with a “Resource busy” error.
• Secure Boot blocking the USB. Many modern PCs have Secure Boot enabled, which can prevent booting from unofficial media. Temporarily disable it in BIOS/UEFI, then re-enable after the reset.
• Choosing a Microsoft account instead of a local account. This method only works for local accounts. If you use a Microsoft account, you must reset the password online instead.

Tips

• Back up data first. While this process doesn’t touch files, it’s always wise to have a backup in case something goes wrong.
• Use a USB 2.0 port if possible—some older BIOS versions have trouble with USB 3.0 during boot.
• Write the ISO using a dedicated tool. If the dd method fails, try using Etcher (available for Mac) to write the ISO directly—it’s more user-friendly.
• Keep the USB drive safe. After you’re done, store it in a secure place. Anyone with physical access to it can reset your PC’s password.
• Set a new password immediately after logging in, and consider enabling BitLocker if you haven’t, to protect your data.

Troubleshooting

• PC won’t boot from USB. Check the boot order in BIOS/UEFI. Ensure the USB is listed first or use the boot menu. Disable Secure Boot temporarily. Try a different USB port (preferably USB 2.0).
• “Resource busy” error in Terminal. Make sure you unmounted the disk with diskutil unmountDisk before running dd. If it still fails, try using /dev/diskX instead of /dev/rdiskX (slower but works).
• Tool doesn’t detect the Windows installation. Ensure you selected the correct drive and that the PC is in UEFI mode if Windows was installed in UEFI. Some tools have separate UEFI and BIOS versions—download the right one.
• After reset, you still can’t log in. If the account is a Microsoft account, this method won’t work. Go to Microsoft’s password reset page on another device. If it’s a local account, try the reset again, ensuring you selected the correct account.
• Mac doesn’t recognize the USB after writing. This is normal—the USB now contains a bootable image, not a standard FAT volume. Don’t worry; it should still boot on the PC.

Frequently Asked Questions

Is this legal?

Yes, as long as you own the computer or have permission from the owner. This method is commonly used by IT professionals to regain access to forgotten passwords.

Will this delete my files?

No, the password reset tool only modifies the SAM database that stores passwords. Your personal files, programs, and settings remain untouched.

Can I use this for a Microsoft account?

No. Microsoft accounts are cloud-based; you must reset the password online via Microsoft’s website. This method only works for local accounts.

How long does the whole process take?

Creating the bootable USB takes about 10–15 minutes on a Mac, and the actual password reset on the PC takes 5–10 minutes, including boot time.

What if I don’t have another Windows PC to create the USB?

You don’t need one—this guide uses a Mac to create the bootable USB, which is the whole point. The Mac’s Terminal and Disk Utility are sufficient.

Is there any way to avoid this in the future?

Yes. Use a password manager, set a password hint, or create a password reset disk (for Windows 7) or use a Microsoft account with two-factor authentication.

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