Boot your computer and access the BIOS.
On most Dell computers, you can rapidly tap the F2 key at the Dell Splash Screen to boot directly to the BIOS. Always follow the on-screen instructions.
Go to the SATA Operation category and select the RAID On option.
Save the changes and the computer will reboot.
Connect the Linux installation media and boot to it to start the operating system installation.
On most Dell computers, you can rapidly tap the F12 key at the Dell Splash Screen to boot to an on-screen boot menu. Use the cursor keys to select the correct option for your media type and hit Enter.
Follow the steps in the How to Install Ubuntu Linux on your Dell PC article to complete the installation.