How To Install Ubuntu Along With Windows legacy BIOS systems

If you’re running Windows on an older PC that uses Legacy BIOS instead of UEFI, you can still enjoy the power and flexibility of Ubuntu without removing Windows. This setup — called dual booting — lets you choose which operating system to use at startup.

Here’s a step-by-step guide to installing Ubuntu alongside Windows on a Legacy BIOS machine.

1. Check Your Current System Type

Before doing anything, confirm that your PC is running Legacy BIOS and not UEFI.

If you’re not sure how to check, follow this guide:
How to Check if Your Computer Uses UEFI or BIOS (in both Linux and Windows)

2. Back Up Your Data

Any OS installation can go wrong, so back up important files to an external drive or cloud storage.
This is especially important if you need to resize your Windows partition.

3. Create Space for Ubuntu

Ubuntu needs its own partition on your hard drive.

1. Press Windows + X and select Disk Management.
2. Right-click the main Windows partition (usually C:) and choose Shrink Volume.
3. Reduce it by at least 25 GB (more if you plan to install lots of software in Ubuntu).
4. Leave the new space unallocated.

4. Download Ubuntu

1. Go to ubuntu.com/download and get the latest Ubuntu Desktop ISO.
2. For older PCs, you might choose a lighter flavor like Xubuntu or Lubuntu.

5. Create a Bootable USB

You’ll need a USB drive (at least 4 GB) and a tool to make it bootable:

• Windows users: Use Rufus
• Select MBR as the partition scheme (important for Legacy BIOS systems).
• Write the ISO to the USB.

6. Boot From the USB in Legacy Mode

1. Plug in the USB and restart your computer.
2. Enter your BIOS setup (usually by pressing F2, F10, DEL, or ESC during startup).
3. Make sure Legacy Boot is enabled.
4. Set the USB drive as the first boot device.
5. Save changes and restart.

7. Start the Ubuntu Installer

Once booted into Ubuntu’s live environment:

1. Click Install Ubuntu.
2. When asked about installation type, select Install Ubuntu alongside Windows Boot Manager.
   • If you don’t see this option, choose Something else and manually select the free space to install Ubuntu.
3. Create the following partitions:
   • Root (/) – at least 20 GB, ext4 format.
   • Swap – equal to your RAM size (optional if you have 8 GB+ RAM).
   • Home (/home) – optional, for storing personal files separately.

If you want a beginner-friendly guide that also covers modern Windows 10 setups, check this:
Beginner’s Guide to Install Ubuntu Alongside Windows 10

8. Install the GRUB Bootloader

The installer will automatically set up GRUB as the boot manager. This lets you choose between Windows and Ubuntu at startup.
For Legacy BIOS, GRUB should be installed to the MBR of your main drive (usually /dev/sda).

9. Finish Installation & Reboot

Once installation completes:

1. Remove the USB drive when prompted.
2. Restart your computer.
3. You’ll see the GRUB menu. Use the arrow keys to choose Ubuntu or Windows.

Troubleshooting

• Windows boots without showing GRUB:
  Boot from your Ubuntu USB, select Try Ubuntu, then reinstall GRUB using the Boot Repair tool.
• No bootable device found:
  Check your BIOS settings and ensure the boot order lists your main hard drive first.

Final Notes

Dual booting is a great way to enjoy both Windows and Ubuntu on the same machine. Just remember:

• Keep backups updated.
• Run Windows Update and Ubuntu’s Software Updater regularly.
• Don’t delete or overwrite partitions unless you’re sure what they’re for.

With this setup, you can switch between productivity in Windows and the open-source freedom of Ubuntu anytime.

Mark Vincent

Tech enthusiast and content creator passionate about making technology simple for everyone. I share practical tips, guides, and reviews on the latest in computers, software, and gadgets. Let’s explore the digital world together!