Why one needs to enable Legacy boot mode in Firmware to install Windows 10 on Linux Laptop?

[Guest]

Almost all videos that I have checked on Youtube that show how to install Windows 10 on Linux Laptops mention that you need to change boot mode from UEFI to Legacy before this task is undertaken.

I don't understand why this step is needed?

Can't I simply delete all Linux partitions and do a clean installation of Windows 10 in UEFI Mode on Linux Laptop with GPT partition scheme on HDD /SSD?

Even if I start with a blank HDD, Windows would automatically partition it to the needed GPT partitions during install.

In case Linux laptops do not come with pre-loaded Windows 10 certificates for Secure Boot to work, that component can just be disabled in the firmware still keeping UEFI boot mode ON.

Am I missing something here?

 

[mazboy]

I'm curious about whether the laptop you are talking about was bought specifically as a "Linux Compatible Computer" with some version of Linux on it, or if it is just some random computer that someone loaded Linux on. There was a period during the time when mainstream (read "Windows") computers were switching to from BIOS to UEFI and it was very, very difficult to load Linux. Some brands offered hardware/firmware that was certified to load/run various Linux flavors.

That's been a while now, and almost all flavors of Linux will load and run on all but the most bleeding edge modern hardware. I personally run Linux Mint 18.xx on various hardware (and FreeNAS on my media server) and haven't had a problem loading it in years. Conversely, when I build computers, I will usually load Linux Mint on it before I do a Windows install (it's free, it's easy, and it lets me play with stuff at a really basic level). I've never had a problem loading Windows on top of Linux, although if I know I'm going to sell the computer I will usually wipe the HDD before I install Windows.

 

[Guest]

Thanks for your response.

The laptop in question is an Acer Laptop that comes pre-installed with Linux as a free OS. I think it's a way to optimize cost of product and in a way allow user to separately buy and install any retail version of Windows 10 that they like be it Home or Pro.

It's a recent laptop. Manufacturer on its website clearly states support for Windows 10 and all drivers are available for download. So practically Windows 10 install should be possible, what I wonder is why to enable Legacy Mode in Firmware (as per guides on Youtube!).

I should be able to wipe all Linux partitions, treat it as a raw HDD or just initialized to GPT and just seamlessly install Windows 10 on it in UEFI mode. Hope my thinking is in the right direction.

 

[mazboy]

If you are so inclined (and I always am when I'm doing an OS install), wipe the HDD (I use DBAN Disk Wipe, available for free here: https://dban.org/ how to use it here: http://www.techfleece.com/2013/08/22/how-to-securely-wipe-your-hard-drive-using-dban/). I do the "Quick Erase" (1 pass writing zeros, then a validation pass. It takes 3-4 hours for a 1TB HDD). I don't know what version of Linux you're using but it should be able to run in UEFI just fine, and I've never bothered to enable legacy boot. If I were you, I would boot into BIOS, reset everything to default, and forget about it.

Get Win10 from here: https://www.microsoft.com/en-us/software-download/windows10 and use the provided Media Creation Tool to put it on a bootable USB stick. Then you can boot your laptop from a USB port and install the OS from there.

Immediately after the install completes, go to "settings->Update & security->Windows Update->Check for updates" and get all the latest stuff downloaded and installed. Once that’s done, you can start installing your applications. It's really easy.