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10 Posts


October 7th, 2019 07:00

Inspiron 7490 BIOS: How to turn off intel 'RAID on', and swith disk mode to AHCI?

  I need to install ubuntu on 7490, but now it blocks by the intel RST mode. The disk can't be found when installing. As guide , i need to turn off 'RAID on', and swith disk mode to AHCI, but how to do that? i realy can't find related items from current 7490 bios. Who can support here?

11 Posts

August 4th, 2020 11:00

Yeah, after running that command, you can use your computer as normal, can apt update|upgrade

October 14th, 2020 03:00


Thanks for the thread. I have this laptop. I have successfully installed the image. However, even when setting up Supergrub as per instructions, I am unsuccessful.

It doesn't seem to see the installed operating systems. II just end up in the blue screen asking to reset, continue boot or always continue boot.

In case its of any help, here is a pastebin from the grub repair tool, run from the live environment of the ubuntu image.

Any help would be much, much appreciated.

1 Message

October 28th, 2020 03:00


I had the same issue it's all about a BIOS setup , you may have to Securtiy boot or something.

Everything works fine for me as I'm using Linux.

By the way it seems that having to switch in BIOS for getting back to Windows seems to fail, as I "lost" the WIN OS launch option. Not needed in my case for now... But seems that if you don't switch on and off securtiy boot option well before switching OS, some issues may happen there, and you can lose dual boot...

17 Posts

November 27th, 2020 02:00

Hi, I wanted to know if this method will work I have a NVME drive (Windows installed on that with the controller being shown as 'Intel(R) Chipset SATA/PCIe RST Premium Controller' in the Device Manger) and want to install UBUNTU on a separate drive, which I want to put in the unused SSD SATA port of my laptop. I just want to install Ubuntu on my laptop somehow, and don't mind loosing windows installation. @evroza @Anonymous 

1.5K Posts

November 27th, 2020 14:00

Well, the issue is you either load a 64bit version of Ubuntu. Microsoft has depreciated the 32-bit version of window. So you can't dual boot a 32-bit system with a 64bit system. You might try running it in a VM that might work?

17 Posts

November 28th, 2020 09:00

Were you able to install Linux safely? I don't seem to find any option in the BIOS where I can change the SATA settings to ACHI . It is just showing two options(as pointed out earlier

  • Disabled 
  • Raid On

Did you follow the steps mentioned by @evroza ? 

I just want to be sure before proceeding with the installation as I have to do a clean install and don't want to end up loosing all the data and at the same time not being able to dual boot.

17 Posts

November 28th, 2020 09:00

Both of the OS Windows and Linux will be 64bit. 
And I think I don't have a extra SATA drive port in my laptop (Dell Inspiron 14 7490), so will have to do the partition of the primary drive and do a clean install. 
I am just worried that with so much effort I want to be sure before proceeding that I will be able to dual boot Windows and Linux. 

1.5K Posts

November 28th, 2020 15:00

Simple, get Macrium Reflect Free, Create a complete disk image. then if it doesn't work out you have a path back to where you are now. Be sure to make the recover USB media, and test it to ensure it boots up correctly.

I don't believe you can dual boot a Windows 10 disk with any other OS, they need to be on a different disk. Perhaps an External USB drive? I could be wrong about this.


February 2nd, 2021 10:00

I am finally able to boot Linux (unmodified Ubuntu 20.04 Desktop) on the Inspiron 7490.

You need:

This grubx64.efi is "more special" than the others in that it allows you to patch the BIOS outside of "Setup", what we need is "PchSetup".

The following instructions work only for BIOS 1.6.0!!! The offsets may change between different versions of the BIOS. Proceed at you own risk!!!

1. Create a normal Linux (in my case Ubuntu) boot USB
2. Replace /efi/boot/grubx64.efi" with the above modified one
3. Boot from the USB, and issue the "setup_var PchSetup 0x44 0" command (this turn off the RAID mode in BIOS)
4. Bonus: if you want to unlock "CFG Lock" as well then type "setup_var CpuSetup 0x3e 0" (I want to unlock CFG Lock to experiment with OpenCore, which I will do next)
5. Power off the machine, put the original grubx64.efi back onto your boot USB
6. Proceed as normal

You will find the NVMe SSD as /dev/nvme0n1.

P.S.: is where I get all the information to do this. Except I had to search high and low to find a modified grub that can patch the PchSetup section of the BIOS.

8 Posts

March 22nd, 2021 02:00

Hello @Big Fat Rat,

It looks promising but being a noob, I have an issue : you say replace grubx64.efi in /efi/boot/grubx64.efi but I get an error message meaning that I do not have enough space on this boot USB

I tried drag n drop then cp command but to no avail. Can you help with the simple command that would do the trick, please ?

1 Message

March 30th, 2021 10:00

This is an amazing find (the comment from 02-02-2021 10:39 AM Eastern Time)  I created an account just to give you praise.  Thank you very much!


WSL2 is impressive but I'm excited to have a native Linux option now.

8 Posts

April 3rd, 2021 11:00


Here is a source of inspiration, but I'm too much of a noob to try to adapt it from Debian :

If someone feels like trying (and explaining in details, if it works !) ...

5 Posts

June 8th, 2021 12:00


I've made another solution based on solution of Evroza.


- no need to handle specific version of grub, the version that comes with ubuntu repos is good

- kernels are updated automatically (they are retrieved from endless OS repos)

- no need to compile the kernel to update it


- for now I've made an explanation of how we can convert an iso to a compatible iso, and it requires a second pc with Ubuntu installed in UEFI mode.

- I used cubic, I don't know if it's compatible with others OS than ubuntu and variants (I used it with debian sid so I think it's compatible with Ubuntu, Debian and variants).

Maybe Gitlab CI permits to generate iso, but I never used these systems, I will investigate this.

This method permits me to install Kubuntu 20.04.2 LTS successfully, and to have a dual boot with a working Windows.


(For French users, I made another explanation here in French: , actually it's a draft, but I think that it will be finished soon)


1. Generation of iso

First download an iso that you want to modify.

Then you can install the PPA of cubic on the other pc with:

sudo apt-add-repository ppa:cubic-wizard/release
sudo apt update
sudo apt install cubic

Then open cubic, it will ask the path to iso file downloaded before.

You can continue, you will obtain a console.

Then copy paste the entire code below:

wget -q -O- | apt-key add -

cat > squashfs/etc/apt/preferences.d/endlessOS.pref << EOF
Package: *
Pin: origin ""
Pin-Priority: 1

Package: linux-image-generic, linux-headers-generic
Pin: origin ""
Pin-Priority: 1000

echo "deb [arch=amd64] master endless" | tee -a squashfs/etc/apt/sources.list.d/endlessOS.list

apt install linux-headers-generic/master linux-image-generic/master

It first add the endless OS key, then add some preferences to avoid that endless OS packages interfere with ubuntu packages, add the repo, and install kernel from endless OS repos.

You can continue with default parameters (just choose the kernel that has been installed, not the old one!), and it will generate a modified iso compatible with Dell Inspiron 9490!

You can burn this iso on a usb key. You just have to pay attention that you utility to burn the iso file must create a UEFI compatible usb key (that's the case with Etcher but many others utilities will do the same)


2. Prepare windows

Boot the Dell Inspiron 7490 on windows, and first disable fast startup (you can follow for example )

Then you can shrink the windows partition (you can follow for example )

That's all for windows.


3. BIOS configuration

Go in the BIOS and disable Secure Boot, this is useful to install nvidia driver.


4. Install Ubuntu or variant

Now you can insert your usb key and boot on it (it's F12 to choose the usb key)

Please don't do updates during installation but after installation, I think it would be better.

Notice that if you do a manual partitionning, you must install GRUB in EFI partition (remember that this laptop is only compatible with UEFI)

Installation would not give you problems, you can reboot on your new install and do updates.

Additionnal things I've done on this pc: I installed tlp and the nvidia driver, rebooted and disabled nvidia graphic card to use less power and to decrease temperature. I also removed Ubuntu HWE, I think it's better but not a requirement.

Another advice: don't erase your usb key to store data on it, keep it as it is, because if your pc doesn't boot, you will have less pain to solve the problem with a working live usb.


Thanks to @pierpiotr who send me his laptop so I can find this solution

5 Posts

June 8th, 2021 13:00

Just one mistake (I don't know how to modify my previous message): commands to copy paste are:

wget -q -O- | apt-key add -

cat > /etc/apt/preferences.d/endlessOS.pref << EOF
Package: *
Pin: origin ""
Pin-Priority: 1

Package: linux-image-generic, linux-headers-generic
Pin: origin ""
Pin-Priority: 1000

echo "deb [arch=amd64] master endless" | tee -a /etc/apt/sources.list.d/endlessOS.list

apt install linux-headers-generic/master linux-image-generic/master

 (in fact just remove squashfs, it was useful when I tried to modify the iso file by myself, without cubic)

17 Posts

June 10th, 2021 06:00

@Nuliel Thanks a lot for your contribution. It will help many users like me  who wanted to install Linux OS on this Inspiron 7490 and didn't receive any help at all from Dell Support.

Also can you please check the link to the you mentioned in the post. It doesn't seem to work.

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