Dual BOOT Windows & Ubuntu

Procedure : how to set up your computer in order to dual boot Ubuntu and Windows.

Install Ubuntu after Windows

A Windows OS should be installed first, because its bootloader is very particular and the installer tends to overwrite the entire hard drive, wiping out any data stored on it. If Windows isn't already installed, install it first. If you are able to partition the drive prior to installing Windows, leave space for Ubuntu during the initial partitioning process. Then you won't have to resize your NTFS partition to make room for Ubuntu later, saving a bit of time.

When a Windows installation already occupies the entire hard drive, its partition needs to be shrunk, creating free space for the Ubuntu partition. You can do this during the Ubuntu installation procedure, or you can see How to Resize Windows Partitions for other options.

If you have resized a Windows 7 or Vista partition and cannot boot up windows, you can use the instructions from Windows Recovery to fix it.

Install Ubuntu

• Download an Ubuntu LiveCD image (.iso) from Ubuntu Downloads and burn it to a disc.
• Insert the LiveCD into your CD-ROM drive and reboot your PC.
• If the computer does not boot from the CD (e.g. Windows starts again instead), reboot and check your BIOS settings by pressing F2, F12, or ESC. Select "boot from CD".
• Proceed with installation until you are asked this question: "How do you want to partition the disk?".
• If you have already partitioned the disk and left space for Ubuntu, install it to that and then follow the rest of the steps.
• Otherwise, choose one of the next two steps.

Automatic partition resizing (recommended)

• Choose the first option, which should say "Install them side by side, choosing between them each startup".
• Specify the size of the new partition by dragging the slider at the bottom of the window.
• Click on "Forward".
• Continue on to Finishing Ubuntu Installation

Manual partitioning

• Choose "Manually edit partition table".
• Listed will be your current partitions.
• Select the partition you want to resize and press Enter.
• Select "Size:", press Enter.
• Select Yes, press Enter.
• Type in a new size in gigabytes for your partition, it's recommended you free up at least 10 GB of free space for your Ubuntu install. Press Enter when happy with your changes. It may take some time to apply the changes.
• Create a swap partition of at least your amount of RAM (if you don't know, 2000 MB is a good value).
• Create a partition for your Ubuntu installation.
• Select "Finish partitioning and write changes to disk".