Deleting And reinstalling Windows 10

[RyanXD]

hello i have a problem when i have two disks in my computer with windows 10 one SSD and one MK2 SSD. i can boot from both without any problems but now i have windows twice on my computer unnecessarily. i would like to know if i reinstall windows on one of the disks if it would be possible to delete windows from the second disk during the reinstallation. if anyone knows the answer it would be very helpful

 

[ChatGPT]

Hi RyanXD — yes, you can reinstall Windows on one disk and remove the other Windows installation. There are two safe ways to do it; the safest is to disconnect the other drive while you reinstall so the installer can’t accidentally use or modify the wrong disk’s boot files. Below are clear steps, warnings, and alternative methods.
Before you start (must-do)

• Back up any personal files from both drives (Pictures, Documents, saved games, product keys, etc.).
• Make a Windows 10 installation USB (Media Creation Tool) and confirm you can boot from it.
• Note which physical disk is which (brand/size). You can identify them later in Disk Management.

Recommended (safest) method — disconnect the other disk

1. Shut down the PC and unplug power.
2. Physically disconnect the SATA (or NVMe) cable and power cable for the disk that you plan to erase later (the disk that currently has the unwanted Windows).
3. Boot from your Windows 10 USB installer.
4. Choose Custom install. Select the target disk (the one left connected), delete its Windows partitions if you want a clean layout, create a new partition and install Windows there.
   • The installer will create the necessary EFI/System partitions on the disk you left attached.
5. When installation finishes, shut down and reconnect the other disk.
6. Boot into your newly installed Windows. If it doesn’t boot automatically, enter BIOS/UEFI and ensure the correct disk is first in the boot order.
7. In Windows, open Disk Management (press Windows+R, type diskmgmt.msc). Identify the other disk, right‑click its partitions and Delete Volume for each partition, then create a new simple volume and format it (or use Disk Management to reclaim the space).
   • If Disk Management won’t delete some system/EFI partitions, use DiskPart (below).
8. Optional cleanup: remove old boot entries if Windows shows multiple entries (msconfig -> Boot tab or use bcdedit).

Why this is safest: with the second disk disconnected the installer cannot place boot or EFI files on the wrong disk. After reconnecting you can wipe the old installation cleanly from inside your working Windows.
Alternative — do it from the installer (more risk)

1. Boot installer with both drives connected.
2. In Custom install, carefully identify the disk you want to reinstall to (use size/manufacturer info).
3. Delete partitions on the disk you are reinstalling to, install Windows there.
4. During or after install you can delete the partitions on the other disk from the installer (Advanced -> Delete) or later from Disk Management.
   Warning: If the installer finds an existing EFI/boot partition on the other disk it might use it for boot files. That can leave you with a broken boot if you later remove that disk. This method works but is riskier unless you are certain which drive holds the system/EFI partition.

DiskPart commands (if Disk Management can’t delete partitions)

• Open an elevated Command Prompt (right-click Start -> Windows Terminal (Admin) or cmd.exe Run as administrator) and use:
  • list disk
  • select disk X (replace X with the disk number you want to wipe — be 100% sure)
  • clean (this removes every partition and data on that disk)
  • create partition primary
  • format fs=ntfs quick
  • assign
  • exit
    Important: clean will irreversibly wipe the selected disk. Double-check the disk number with list disk and the sizes.

Removing extra boot entries

• If you later see two Windows boot entries, you can remove the unused one:
  • Run msconfig -> Boot tab -> select the unwanted entry -> Delete.
  • Or use bcdedit carefully (I can give exact commands if you paste bcdedit /enum output).

Other notes

• Activation: If your PC had a digital license linked to the motherboard or Microsoft account, Windows 10 should reactivate automatically after reinstall.
• UEFI vs Legacy: If your PC uses UEFI, the installer uses EFI system partitions. Disconnecting the other disk avoids cross-contamination of EFI partitions.
• If you prefer, tell me:
  • Which disk number (from Disk Management) is the one you want to keep and which to remove (or tell me sizes/labels),
  • Whether your firmware shows UEFI or Legacy/CSM,
    and I’ll give exact step-by-step commands to delete only the unwanted Windows safely.

Which method would you prefer — I can walk you through the exact steps for either method.

 

[datawizard0103]

hello i have a problem when i have two disks in my computer with windows 10 one SSD and one MK2 SSD. i can boot from both without any problems but now i have windows twice on my computer unnecessarily. i would like to know if i reinstall windows on one of the disks if it would be possible to delete windows from the second disk during the reinstallation. if anyone knows the answer it would be very helpful

Hey, yes you can definitely do that. When you reinstall Windows on one disk, during the setup you’ll see all your drives listed and you can select the second disk and delete its existing Windows partitions. Just make sure you don’t touch the drive you want to keep. After that the installer will create fresh partitions on your main disk and you’ll have only one Windows installation. Backup anything important from the second disk first because deleting partitions will erase all data on it.