Windows 10: Accidentally activated C partition no boot now. What’s up?

Got a computer question. I'm hooking up my dad's old computer right so I reinstalled Windows 10 and a disk management. I activated the wrong partition by accident said to change the partition to an active operating system and I did but now my computer won't even launch the drive won't even boot think you could help me out?

:)

 

Multiple Boot Managers and/or active partitions error

I don't know what you did to fix previously but with the commands above should rebuild the the partition unless the partition itself is corrupted preventing you to run those commands.
Let's try another way:

1. Download the Macrium Rescue disk: MacRescue.iso - Google Drive
2. Using a USB stick to create a bootable USB with: Rufus - Create bootable USB drives the easy way
3. Boot up the PC with UEFI Mode and follow the screen shots to rebuild the EFI System partition.
   NOTE: The title must show: ..... Win PE 10 [UEFI] for step 3 to work since your Windows installed with GPT disk.

IMPORTANT: make sure you use the correct disk in step 2, in your case is disk 1

 

Move Win7 64 image from a partition NTFS to a new drive

EDIT: After reading your first post again, is there any reason that you would now need GPT? Are you just trying to move the windows install to a new disk or is there a new motherboard involved?

If you are already booting to an NTFS partition, then it makes me wonder if after copying to the new drive, the partition isn't getting marked as Active.

Following the same steps I posted above for startup repair, you can get to a command prompt and use diskpart to see if this is the case.

Code: In the command prompt: diskpart list disk select disk 0 (disk number may be different if you have other disks connected.) list partition select partition 0 (partition number number may vary, but you want to see the boot partition which is the same as your windows partition according to the screenshot on the OP) detail partition (This should have Active: Yes or No. If it says no, since we have the partition selected, you can just use the following command in diskpart) active[/quote]

 

unmark a partition as "active"

After changing to active partition my computer doesn't boot so what can I do now?