After New Manjaro installation grub doesn't see windows 10

[megavolt]

@DAS

Model: ATA Samsung SSD 850 (scsi)
Disk /dev/sdc: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 256GB 256GB ext4 boot, esp

Seriously? Your efi partition have to flagged with boot, esp. It is not BIOS.

@linux-aarhus

Manjaro installation

Now that you have partition sizes defined let start and the numbers are MB which is the unit Calamares makes use of

1. Reboot your computer to the live USB media.
2. Launch the graphical installer - it is named Calamares.
3. Follow the guide until you reach the Disk selection/preparation
4. Select Manual partitioning → Next.
5. Select the correct disk selected - should be easy to see.
6. EFI PARTITION
   Skip if using BIOS/MBR
   Select the unpartitioned space → Create
   a. Size → input 512
   b. Filesystem → select FAT32
   c. Mountpoint → select /boot/efi
   d. Flags → check boot → OK
7. SWAP PARTITION
   Select the unpartitioned space → Create
   a. Size → input 2048
   b. Filesystem → select linuxswap → OK
8. ROOT PARTITION
   Select the unpartitioned space → Create
   a. Size → input 20480 (min. recommended size)
   b. Filesystem → select ext4
   c. Mountpoint → select / (root) → OK
9. HOME PARTITION
   Select the unpartitioned space → Create
   a. Size → Use remaining
   b. Filesystem → select ext4
   c. Mountpoint → select /home → OK