On this page
Troubleshooting starts by naming the symptom, not by changing several settings at once. Record what the computer shows, protect the evidence, and choose the matching section below. Each card gives a safe first move and routes to the lesson with the full explanation.
You do not need to know the cause before using this page. Start with the heading that most closely matches what you can see.
Run only its safe first checks. If the symptom remains, open the linked lesson for the full explanation instead of trying several unrelated fixes. That preserves useful evidence and makes it easier to undo one controlled change.
The USB is not listed in the boot menu
What it probably means: the USB was not written as bootable media, the port or drive was not detected, or the firmware is not presenting the expected UEFI entry.
Safe first checks: shut down, connect the USB directly rather than through a hub, reopen the one-time boot menu, and identify it by brand and capacity. If absent, recreate it from the official ISO.
Do not: disable Secure Boot or change unrelated firmware options as a universal first fix.
Continue with Ubuntu USB Not Booting? Use These Safe Checks.
The computer starts Windows instead of the USB
What it probably means: the normal internal drive remained first in the boot order; this does not prove the USB is bad.
Safe first checks: restart with the USB connected and open the one-time boot menu using the model’s documented key. Choose the USB’s UEFI entry on a modern system.
Do not: erase Windows or permanently rearrange every boot setting merely to reach a one-time installer.
Follow How to Boot Ubuntu from a USB Drive.
The screen turns black after selecting the USB
What it probably means: the system began loading but met a graphics, firmware, USB-writing, or image-integrity problem. A black screen alone does not identify which one.
Safe first checks: wait briefly, note whether a logo or error appeared, retry a directly connected port, and recreate the media from a completed official download. If the boot menu offers the official safe-graphics option, use it for diagnosis and record whether that changes the result.
Do not: apply an unverified kernel option or disable several security settings at once.
Use the USB boot troubleshooting lesson and the official install guide linked below.
The installer reports an Intel RST conflict
What it probably means: the active storage-controller arrangement is not supported by this Ubuntu installation flow.
Safe first checks: stop the installer, decide whether Windows must be kept, back up files, and record the firmware’s current storage setting. If Windows must remain, prepare Windows through Canonical’s complete AHCI procedure before changing the controller.
Do not: disable RST, RAID, or VMD blindly. Windows can stop booting and RAID-managed data can become inaccessible.
Read Intel RST, VMD, RAID, and AHCI Explained for Ubuntu.
Only the USB drive appears
What it probably means: the live system can see its own installer media but not the expected internal disk.
Evidence to compare: a device around 114–123 GB, model SanDisk, with VFAT and /cdrom is strong evidence of the installer USB. Those clues are more useful together than the device name alone.
Safe first checks: return to the live desktop and run the read-only command from Lesson 4.1. Compare model, total capacity, filesystem, and mount point. Then check whether firmware sees the internal drive.
Do not: click New partition table, Format, +, −, Change, or Next while the only visible device is the USB.
Go directly to Ubuntu Installer Shows Only the USB Drive: Find the Missing SSD.
The internal SSD or NVMe disk is missing
What it probably means: Ubuntu cannot currently reach the expected internal disk.
If firmware sees the disk but Ubuntu does not, investigate RST, VMD, RAID, or another controller configuration. If firmware also does not see it, a hardware, connection, disabled-drive, or firmware problem becomes more likely.
Safe first checks: inspect firmware without changing settings, write down whether the disk is listed, and compare the result with lsblk in the live session.
Do not: assume the internal disk must be /dev/sda. It may be nvme0n1, sda, or another name.
Start with the missing-drive diagnosis, then use the storage-controller explanation if firmware detects the disk.
Manual partitioning shows only one VFAT USB partition
What it probably means: you are looking at the installer media, not a valid internal-disk layout. The /cdrom mount point is another strong clue.
Safe first checks: cancel or go back without applying changes. Identify every visible device from the live desktop.
Do not: create a partition table or format that VFAT partition. That can destroy the installer you are currently running.
Review Ubuntu Disk Setup Explained only after finding the missing SSD.
A BitLocker warning appears
What it probably means: Windows encryption affects the installer’s ability to understand or safely resize the Windows layout, or the planned firmware change may require a recovery key.
Safe first checks: confirm whether Windows must be kept, find and back up the recovery key, and create a separate file backup. Read the current Ubuntu screen and guidance before decrypting anything.
Do not: delete encrypted Windows partitions as a dual-boot shortcut or disable encryption before securing recovery information.
Use BitLocker and Ubuntu Dual Boot: Prepare Windows Safely.
Install Alongside Windows is missing
What it probably means: Ubuntu does not currently see a safe side-by-side arrangement.
Possible causes include an inaccessible RST-managed disk, encryption or layout constraints, insufficient usable space, or Windows state that needs preparation. The missing choice does not identify one cause by itself.
Safe first checks: verify that the internal disk appears, confirm the Windows encryption state, and return to Windows without modifying partitions if Windows must remain.
Do not: choose Erase disk as a substitute unless the deliberate decision is to remove Windows and all wanted data is backed up.
Read the BitLocker lesson and the disk-setup comparison.
Windows will not boot after changing AHCI, RST, RAID, or VMD
What it probably means: Windows was configured for the previous controller mode or relies on the previous storage arrangement.
Safe first checks: stop making further changes, restore the recorded original firmware setting when that is part of your documented recovery plan, and use Windows recovery information. Follow Canonical’s complete current Windows-to-AHCI procedure rather than an isolated registry instruction.
Do not: alternate several controller settings, delete Windows partitions, or format the disk.
Return to the RST, VMD, RAID, and AHCI lesson and Canonical’s Windows-to-AHCI guide in its Official documentation section.
Installation returns to the USB installer after restart
What it probably means: the computer booted the USB again.
Safe first checks: shut down, remove the installation USB, and start the computer. If needed, choose the internal Ubuntu UEFI entry in the one-time boot menu.
Do not: start a second installation or erase the disk again.
Review Complete the Ubuntu Installation and Set Up Your First Boot.
No boot device appears after installation
What it probably means: firmware did not select or expose the installed Ubuntu boot entry, or installation did not complete on the expected internal disk.
Safe first checks: confirm that the USB is removed, inspect the one-time UEFI boot menu, and confirm that firmware still detects the internal disk. Record every exact message.
Do not: create a new partition table or change the storage controller without first confirming what was installed and preserving data.
Use the first-boot recovery section and, when it does not resolve the issue, take the information below to Ubuntu’s official support channels.
Wi-Fi does not work in the live session
What it probably means: the live image lacks a required driver or firmware, the adapter is disabled, or the network itself is unavailable. It does not automatically mean installation is impossible.
Safe first checks: verify airplane mode, try Ethernet or USB tethering when available, record the adapter model, and decide whether network access is essential before installing. The third-party software option can help supported devices, but it is not a guarantee.
Do not: assume an unrelated internet driver download is safe or compatible.
Use Try Ubuntu Before Installing: Test Your Hardware First and the hardware links in its Official documentation section.
The installer freezes or closes
What it probably means: possible media, memory, graphics, storage, or installer failure. A single freeze does not identify the component.
Safe first checks: photograph or record the last visible message, wait for disk activity to settle, recreate and optionally verify the USB, and retry the live session’s hardware checks. If storage changes may already have started, determine the disk state before another installation attempt.
Do not: power-cycle repeatedly during visible disk writing or keep confirming the same destructive plan without reviewing the error.
Start with the USB troubleshooting checks and use Ubuntu’s official support channels when the exact error is not covered.
The wrong disk was selected but installation is not confirmed
What it probably means: you caught the error in time.
Safe first check: go back or close the installer without accepting the final destructive confirmation. Reconnect only the devices you actually need and identify the target again by model and capacity.
Do not: select Next or Install to find out what the screen does.
Return to Ubuntu Disk Setup Explained: Erase, Alongside, or Manual.
How to ask for help
A precise report gives a helper evidence instead of asking them to guess. Include:
- computer manufacturer and exact model;
- intended result: replace Windows or keep it in dual boot;
- Ubuntu version and where the image came from;
- exact screen title, message, or error wording;
- whether BIOS/UEFI detects the internal disk;
- whether Windows uses BitLocker or Device Encryption;
- current storage mode—RST, RAID, VMD, or AHCI—when known;
- output from the exact
lsblkcommand in Lesson 3.2; - what changed immediately before the symptom.
Use a photograph only after checking what it reveals. Redact serial numbers, BitLocker recovery keys, email addresses, and Wi-Fi names when desired. Never publish passwords, account recovery codes, or disk-encryption passphrases.
lsblk -o NAME,SIZE,TYPE,FSTYPE,MODEL,MOUNTPOINTSThe prompt is not part of the command. Explain that the output came from the live Ubuntu session and state which device you believe is the USB, but invite the helper to verify that interpretation.
Practice
Knowledge check
Read the evidence. A manual-partitioning screen shows one 114.6 GB SanDisk device with VFAT
and /cdrom. State the safe next action, the controls that must not be used, and the two lessons
that diagnose the disk and storage-controller configuration.
What to learn next
If Ubuntu now starts from the internal disk, the installation series is complete. Ubuntu Desktop Controls, Linux Terminal Basics, Installing Software on Ubuntu, and Linux Files and Permissions are planned follow-ups. They are intentionally not linked until complete lessons exist.