windows - Remove Main Partition (C:) and make other Parition (D:) the main

Basically I installed windows 8 and windows 10 on the same HDD. I created a partition on the HDD for each. I started with windows 8 on C: and then created a partition (D:) and installed windows 10 on it. Now I want to keep windows 10 and remove 8 (on C:) but I can't delete the partition because there are boot files and paging on (C:).

What do I need to do this? I've been googling for a while with no luck.

Answer

Remove Main Partition (C:) and make other Parition (D:) the main

Now I want to keep windows 10 and remove 8 (on C:) but I can't delete
the partition because there are boot files and paging on (C:).

Use the below instructions with gparted to set the Window 10 partition as the active boot partition, confirm that it reboots properly as you would expect, and then afterwards wipe the Windows 8 disk partition from Disk Management, reformat, and so on.

Use a GParted Live CD to make a Linux or Windows drive Active

How to use the free GParted CD to mark a Linux or Windows Primary
partition Active.

1. Download the latest stable release of
   GParted and create the
   Live CD from the ISO file.


2. Boot from the Linux Live CD and complete
   the three user-input requests. GParted will run automatically.
   
   
   
   • Right-click the Primary partition you wish to make Active and select
     Manage Flags.
   
   
   • In Manage Flags on ..., tick (to enable) the boot check
     box to make the partition Active.
   
   
   • Click Close and exit the partition utility
   
   


3. Restart your computer.

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To burn a Live CD instructions, download the gparted ISO and then see How to burn a DVD on Windows for the instructions how to burn an image to a disc with Windows 10; you can use a CD rather than a DVD for gparted but the steps should be very similar regardless and self explanatory from there.

How to burn a DVD on Windows

Once you’ve downloaded the file, follow the instructions below to burn
your DVD, depending on which version of Windows you are currently
using.

Windows 7 / 8 / 10

1. Right-click on an ISO image and choose 'Burn disc image'.




2. Select a disc burner (drive) and choose 'Burn'. If you check 'Verify disc after burning', it will confirm that the ISO image has been burned correctly.

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