Your dual boot installed fine, but Ubuntu shows an error when you open the Windows drive, or opens it read only so nothing can be saved. Nine times out of ten the drive is not damaged — Windows never actually shut down. This is the Fast Startup problem, and the fix takes two minutes.
Fast Startup is a Windows feature that trades a real shutdown for a partial hibernation, so the next boot feels faster. The cost lands on the other operating system: Windows keeps its NTFS drives in a hibernated, locked state, and Ubuntu's NTFS driver will refuse to write to them — or refuse to mount them at all. Here is what is happening, the exact message Ubuntu shows, and the setting that ends it permanently.
When you click Shut Down with Fast Startup enabled, Windows does not fully close. It logs you out, then hibernates the system session — the kernel and the state of every mounted drive are saved into the hibernation file, ready to be restored at the next power-on.
Windows itself never notices, because it resumes its own saved state. Any other operating system that touches the drive sees the truth — it was never really closed.
The refusal in the panel above is Ubuntu being careful, not broken. Writing to an NTFS drive that Windows believes it has hibernated can corrupt the file system, because Windows will later restore its saved view of the drive and overwrite whatever Ubuntu changed.
Some guides suggest forcing the mount or deleting the hibernation file from Linux. Do not. That is exactly the write that causes corruption. The correct fix is on the Windows side and takes one setting.
Boot into Windows and change the one setting. After this, every shutdown is a real shutdown and Ubuntu gets full access to the drives.
The trade-off is honest and small: Windows cold boots a few seconds slower. On any machine with an SSD you will barely notice, and you gain drives that behave in both systems.
If the Fast Startup checkbox is missing entirely, it usually means hibernation itself is disabled on your Windows. There is also a stronger command route — running powercfg /h off in an admin Command Prompt turns hibernation off completely, which removes Fast Startup with it.
powercfg /h off also deletes the hibernation file and removes the Hibernate option from the power menupowercfg /h onPick the checkbox if you ever use Hibernate. Pick the command only if you never do — the freed disk space (the hibernation file is a large share of your RAM size) is a nice bonus on a small SSD.
If Ubuntu is already open and the drive will not mount, do not force it. Go back to Windows once, properly this time.
shutdown /s /f /t 0 for a guaranteed complete shutdownAfter one clean shutdown, Ubuntu mounts the drive normally and the whole problem simply stops being a part of your dual boot life.
Fast Startup is one of the preparation steps in the full dual boot installation — watch the whole method done live in the video.
▶️ Watch Full VideoBarely. Windows will take a few extra seconds on a cold boot because it loads everything fresh instead of restoring a saved session. On an SSD system the difference is small enough that most people never notice it after the first day.
That is the same problem in its milder form — Ubuntu mounted the drive read only because it found the hibernated state. Do one full shutdown from Windows using Restart or the shutdown command on this page, then turn Fast Startup off so every shutdown is a real one.
It works, because a restart always closes the drives fully — but it is a habit you have to remember forever, including after every Windows update and every quick power-off. Turning Fast Startup off once is the permanent answer, and it costs you only a few seconds of boot time.