How to switch back to Windows 10 from Ubuntu

My specific issue is that although I have the Windows 10 ISO and the flash drive that I used to install Linux, I am unable to put the ISO files onto the Drive. Specifically, I'm using an SD card reader in my USB slot, and the SD card is 64GB. It worked fine for Ubuntu, and I deleted all of the files and tried to replace them with the contents of the Windows ISO, but one of the files won't move to the SD card. My understanding is that the individual file is too large rather than the card not having enough storage. Is there any way around this? I don't have a disk drive or any DVDs to burn it onto. I used a software on Windows to put the ISO on my SD card originally, but that doesn't seem to be an option on Ubuntu. I should also note that I completely removed Windows because I was having issues adjusting the partitions, so Windows is completely gone and I would like to completely get rid of Ubuntu to replace it with Windows 10.

As Nmath said in the comments, I'm sorry you feel you've been chased away by the community - that's not what AU is about. Welcome to AU!

It's obviously not much of an Ubuntu question (asking how to uninstall it!) though I don't think it's technically off topic as you're asking how to do something within Ubuntu.

I think your best option - if possible - is to find someone with a working Windows machine to create Windows installation media on your SD card to use with your USB adapter (or buy / borrow a USB drive from someone).

It may be that your USB is formatted as FAT rather than ExFAT - that's likely to be the reason you can't put a big file on there (4GB is the limit for any file in FAT).

From Ubuntu, it is possible to create installation media - here are some online guides I've found; I've not tried them myself but they are sites I've used before and generally found useful.

https://itsfoss.com/bootable-windows-usb-linux/

https://www.makeuseof.com/how-to-create-windows-bootable-usb-linux/

https://www.omgubuntu.co.uk/2017/06/create-bootable-windows-10-usb-ubuntu

Edit (2023): I’ve now had the chance (need!) to test out how to do this as I had a need to reinstall Windows on my wife’s computer - it was actually very easy to create the installation media - see How can I create a Windows bootable USB stick using Ubuntu? for answers on this including how I did it this year. The comment by @C.S.Cameron is pretty much spot on - it’s easy but woeUSB didn’t work for me.

This isn't what you're asking, but I would suggest thinking again before ditching Ubuntu and installing Windows. Once you've got your installation media sorted, do consider the option of dual boot if you have enough hard drive space. Install Windows first, disable fast start up, download the Ubuntu installation media and create a USB ISO (eg using Rufus in Windows) then install Ubuntu alongside. There are lots of guides online - do an online search for 'Ubuntu dual boot' for example - or I explain how I did it in the link below. For me - when I was used to Windows and wanted to try Ubuntu, it was a great way to try out the OS without fear of losing an OS I knew how to use. Moving forward 3 years, and I now have just Ubuntu on my home computer and laptop.

You said in your previous post that you needed Zoom - that's easily installed from the software centre (Zoom client). You will find equivalents of virtually every program you can install in Windows available on Ubuntu, either via the software centre, or from the company's website for direct download. For my purposes, I found literally everything I wanted in Ubuntu with only 2 exceptions (-1-: iTunes to sync my iPhone's music with my computer; -2-: software to open a shared Outlook calendar). I wrote a detailed log of what I did here in case it's any use: How to set up a system for UK medical practise You'll see very quickly that I'm not an IT professional at all but I have found it immensely rewarding to switch from Windows to Ubuntu - more than I thought it would be. It did take some effort but I am very pleased I changed.

I appreciate that's a relatively niche area, but it gives you a flavour of what is possible and a lot of the software I installed is generic and the kinds of things most people would want: equivalents for Word / Excel / Powerpoint / PDF editor / Photoshop equivalent / real versions of Teams / Zoom / Dropbox / Minecraft (for my son!) - as well as some profession-specific stuff like medical image viewing software.

Whatever you decide to do, good luck with it.

but one of the files won't move to the SD card. My understanding is that the individual file is too large rather than the card not having enough storage.

Your problem is most likely that your SD card is formatted as FAT32 (or vfat in Linux) and you are trying to copy the sources/install.wim from the Windows ISO which is larger than 4 GB, whereas 4 GB is the absolute maximum size a FAT32 file can occupy (unfortunately this is a design limitation of the file system).

So, yes, in this case, you won't be able to extract the whole ISO content onto a FAT32 formatted SD card, and you need to format the card using a different file system, such as NTFS. If you're running a recent version of Linux, mkfs.ntfs should be able to format your SD card to NTFS, and then you will be able to extract all the ISO content, including that install.wim file that is larger than 4 GB, onto the SD card.

However now your problem becomes that not all computers can boot Windows media that has been extracted to NTFS (and also a lot a computers with an SD reader cannot boot directly from SD card — You have to use a USB to SD card reader). If the computer you are trying to boot is recent, i.e. less than 5 or 10 years old, there's actually a good chance that UEFI boot will support NTFS, so you should definitely try to extract the ISO content to your NTFS formatted SD card and see if that boots (again, using an SD to USB adapter, because it's unlikely you'll be able to boot from an integrated card reader). Make sure your BIOS is set to boot in UEFI mode rather than Legacy when doing that though.

Now, if that doesn't work, it means that your UEFI firmware does not include an NTFS driver, so it'll take a bit more involvement to create your Windows boot media from Linux. I would start by looking at WoeUSB and see if that works for you.

Concerning the boot medium itself: I made pretty good experience with using ventoy. Here you need not modify your ISO file, just put it on the drive ...

https://www.ventoy.net

You can put more than one ISO on the stick, you can boot both bios and uefi. It also takes care to format your stick / card in a way that you can write files larger than 4G (exFat)