How to Fix a Windows 11 Bootable USB That Is Not Booting on Lenovo X390 Yoga

Introduction

Have you ever created a bootable Windows 11 USB using Rufus, only to discover that your Lenovo laptop refuses to boot from it?

I recently encountered this issue while preparing a Lenovo ThinkPad X390 Yoga for Windows 11 installation.

The USB flash drive was successfully created using Rufus, and the laptop could detect it in the BIOS boot menu. However, whenever I selected the USB HDD option, the screen went black and displayed a blinking cursor instead of loading the Windows installation interface.

After investigating the issue, one important configuration stood out: the USB drive had been created using the MBR partition scheme, while the laptop was configured to boot using UEFI.

This article explains how to troubleshoot and resolve this problem.

The Problem

The initial setup was as follows:

Laptop: Lenovo ThinkPad X390 Yoga
Operating system: Ubuntu
Installation media: Windows 11 bootable USB
USB creation tool: Rufus
Partition scheme: MBR
Boot mode: UEFI

The laptop recognised the USB flash drive in the BIOS, but selecting it from the F12 boot menu resulted in a blinking cursor rather than launching Windows Setup.

This suggested that the laptop could detect the USB device but was not successfully loading its bootloader.

Step 1: Access the Lenovo BIOS Setup

First, shut down your Lenovo ThinkPad X390 Yoga.

Insert the bootable USB flash drive.
Switch on the laptop.
Immediately press F1 repeatedly to enter BIOS Setup.
Navigate to the Startup section.

In the BIOS, locate the boot configuration settings.

Check that USB boot is enabled and that the laptop is configured to use UEFI boot mode.

Step 2: Check the USB Boot Priority

Navigate to:

Startup → Boot

The Lenovo BIOS should display available boot devices.

For example, you might see:

Ubuntu
USB CD
USB FDD
NVMe SSD
USB HDD – VendorCo ProductCode
PXE Boot

The USB HDD entry represents the connected flash drive.

If necessary, move the USB device higher in the boot priority list.

Save the changes by pressing F10.

Important: Changing boot priority does not necessarily fix an incorrectly configured bootable USB. It only determines which device the laptop attempts to boot first.

Step 3: Identify the MBR and GPT Compatibility Issue

This was an important discovery during troubleshooting.

Rufus supports different partition schemes, including:

MBR (Master Boot Record)
GPT (GUID Partition Table)

Modern Windows 11 installations on UEFI-based systems should generally use GPT.

For this reason, recreating the USB using GPT and UEFI is a sensible troubleshooting step.

The recommended configuration is:

Note that Rufus may use NTFS when the Windows installation files exceed FAT32's file-size limit. This is normal, and Rufus provides mechanisms to support UEFI booting from such media.

Step 4: Recreate the Windows 11 Bootable USB

On another working Windows computer:

Download and install Rufus.
Download the official Windows 11 ISO from Microsoft.
Insert an 8GB or larger USB flash drive.
Open Rufus.
Select your USB device.
Select the Windows 11 ISO.
Choose GPT as the partition scheme.
Select UEFI (non-CSM) as the target system.
Choose the appropriate file system.
Click START and wait for the process to complete.

Warning: Creating the bootable USB will erase its existing contents. Back up your files before proceeding.

Official Windows 11 download:

https://www.microsoft.com/software-download/windows11

Rufus download:

https://rufus.ie/

Step 5: Configure the Lenovo BIOS for UEFI Boot

After recreating the USB, return to the Lenovo BIOS.

Check the following:

UEFI/Legacy Boot: UEFI Only
USB Boot: Enabled
F12 Boot Menu: Enabled

Initially, leave Secure Boot enabled. If you encounter a Secure Boot error, investigate the USB's bootloader compatibility before changing security settings.

Save the configuration using F10.

Step 6: Boot from the Windows 11 USB

Now attempt to boot from the newly created USB.

Insert the flash drive.
Shut down the laptop.
Switch it on.
Immediately press F12 repeatedly.
Select the USB HDD entry or the UEFI USB entry, if available.
Press Enter.

If the USB was created correctly and is compatible with the laptop's firmware, Windows Setup should load.

You should eventually see the Windows 11 installation screen.

Important: What About Existing Ubuntu Installation?

One important consideration is that the Lenovo ThinkPad X390 Yoga originally had Ubuntu installed.

If you intend to replace Ubuntu completely with Windows 11, make sure you have backed up your important files.

If you want to keep both operating systems, you need to plan a dual-boot installation carefully.

Do not delete or format existing partitions without understanding their purpose.

A clean Windows installation can remove Ubuntu and its bootloader, depending on the partitions selected.

Lessons Learned

This troubleshooting experience highlights several important points:

A laptop detecting a USB device does not necessarily mean the USB is bootable.
BIOS boot priority and USB boot configuration are different things.
UEFI and GPT are generally the appropriate combination for modern Windows 11 installation media.
Rufus settings matter when creating installation media.
Always consider existing operating systems and data before performing a clean installation.

Conclusion

If your Lenovo ThinkPad X390 Yoga recognises a Windows 11 bootable USB but displays a blinking cursor when you attempt to boot from it, recreating the USB using Rufus with GPT and UEFI settings is a good troubleshooting step.

However, remember that a blinking cursor can have other causes, including corrupted installation media, an incompatible bootloader, or firmware configuration issues.

The key is to troubleshoot systematically rather than immediately assuming the USB flash drive is faulty.

Have you encountered a similar problem when installing Windows 11 on a Lenovo ThinkPad? Share your experience and solutions in the comments.