I want to create ext4 partition in my internal hard disk from windows 10.
I have seen many questions but all of them mention to partition with external hard disk.
I wanted partition in internal harddisk and not external.....
Firstly, unless you're running non-stock file-system drivers, other 3rd party utilities, or a VM, you cannot create an ext4 partition from Windows.
You can create space for the partition in Windows using Windows' Disk Management (type Disk Management into Cortana). You'll probably need to shrink your existing partition, which can be done by right-clicking and then selecting shrink. This is not always straightforward, and you may need to do it from Windows 10 install media and diskpart.exe. Windows 10 install media can be acquired from the Windows 10 Media Creator on Microsoft's website for free (you may need to enter your product key, which you can get from Produkey by Nirsoft) and you can burn it to a DVD or make a Bootable USB drive.
After you shrink existing partitions, you have room for ext4, but again, you'll need to use a VM which can be given device level access, bootable Linux install media, or file-system drivers that grant Windows the ability to do ext4 stuff. Note that you will not be able to read that filesystem from Windows without those 3rd party drivers or other 3rd party software.