bilsch wrote:
I currently have no Windows system on any PC. I have Ubuntu. I want to
purchase and download a Win10 bootable install iso for use on another PC
(an old Dell Inspiron N4110 laptop). I can make a bootable USB stick
using linux command line something like:

dd if=windowsinstall.iso of=/dev/sdb

I know how to do that.

What i need to know is where to purchase and download the iso file that
will boot the laptop into the Windows 10 installation routine. I assume
I will get a long registration code when I purchase the file that I will
need to enter during installation. I prefer to get the file from
Microsoft if possible. TIA. Bill S.

Using woeusb (in a VM), I was able to make a
USB stick with the current Win10 download ISO.

Win10_1809Oct_English_x64.iso 5,075,539,968 bytes

The "install.wim" in sources folder on that ISO, is
too large for FAT32. The USB stick partition used by
woeusb, should be NTFS. As woeusb handles NTFS OK.

*******

Before I started my install, I backed up the MBR using "dd".

dd if=/dev/sda of=~/mbrsda.bin bs=512 count=1

Then, I install WIN10PRO, which breaks Ubuntu boot.

I boot a LiveCD and do this, and this puts back the
Ubuntu boot code for the first stage of GRUB.

dd if=~/mbrsda.bin of=/dev/sda bs=440 count=1

Reboot, now the Ubuntu menu doesn't have WIndows yet.

sudo update-grub

You should see "Windows 10" mentioned near the end of
the detection, if "osprober" package is present to do
the job.

On the next reboot, the GRUB menu will be present again,
and you can cursor down to the Win10 entry when wanting
to chainload Win10.

It even works with only a single primary partition left
before the install begins.

https://i.postimg.cc/c4crqh7D/WIN10-done.gif

Paul