On dual boot KDE+Windows, wanting to delete Windows partition

[Aragorn]

First of all, you don’t really need to merge them into a single partition. You can simply mount them somewhere and split off some stuff from your root filesystem, as per this guide…

[Tip] Root filesystem full but got a spare partition sitting around? Split off some stuff!

Difficulty: ★★★☆☆ Introduction As you should all already know by now, GNU/Linux is a FLOSS variant of the UNIX operating system design, and UNIX does not know the concept of drive letters, nor does it approach storage from the vantage of having different volumes. Instead, everything is mounted into a uniform directory hierarchy, so that regardless of what physical medium any particular group of files resides on ─ even if this physical medium is actually located in another computer across the …

Secondly, there is a way to merge all of your partitions into a single filesystem without having to physically move or merge anything, but it’s tricky and not for the faint of heart, and you will need the btrfs filesystem for that — ext4 cannot do this.

If you’re a newbie, then my advice would be to just make a backup of all your data on an external medium or on a second internal drive, and then repartition and reformat your main drive, reinstall, and restore your backup.