I just installed Ubuntu and haven't started using it yet. My hard drive is divided into messy partitions here and there, so now I want to uninstall and re-install again.
I don't have a Windows 10 bootable DVD/USB and my PC uses UEFI.
So, is it enough to just set boot options, default boot to Windows bootloader before deleting the partitions with Ubuntu, using Windows Disk Management tool?
Or will I need Windows installation disk still?