Windows 8.1 can't access NTFS partitions

tbo2903

New Member
Messages
9
I have a strange error. Suddenly Win 8.1 (on partition F) can't read anymore my other partions on the same drive, also it coudn't read my external USB drive.

When clicking on the partitions c: or d: it says 'cannot access local device' and 'device not ready'.

I have a dual boot system with Windows 7 and 8.1. I can boot into Windows 7 and read all partitions. I also checked the MBR which looks fine. I also have controlled in Computer Management that all drives have a letter assigned.

However Windows 8.1 can read my USB drives and the installation DVD of Windows 8.

Clicking on properties of e.g. drive c:\ there is of course no security tab, so it shouldn't be a question of permissions. Also no error codes in event log.

Booting in safe mode does still does not solve the problem. Of course Windows 8.1 can read perfectly its partition where it has been installed.

I know, a repair or refresh might be the solution, but if anyone has a good idea where to look because if possible I want to avoid it.

Checked also with my different antivirus and spyware programs. All comes clean.
 

My Computer

System One

  • OS
    Windows 8
I had a similar problem, i think that windows 7 messes up partitions that touch Windows 8, i think the solution is to Update Windows 7, at least that is what i think because mine was outdated(i had windows update turned off), but to be honest i uninstalled windows 8 just after noticing problems with my partitions(that was when windows 8 was out), now in windows 8.1 i don't see the problem, but in my case windows 7 deleted files created on windows 8 and Vice versa, i really, really really, really, suggest you to backup your files, i have 9TB of space, you can't imagine the pain, good luck & please post back what you made to solutionate your problem, i want to know as well.
 

My Computer

System One

  • OS
    Win 8
    Computer type
    PC/Desktop
I already have hybrid boot off. But here's what I've found out so far.

As the disk management recognizes the partitions and there is a drive letter, I opened a command prompt and did the following:

1) diskpart

2) list volume

I saw that all volumes except where Windows 8.1 has been installed and of course the 200 Mb system partitions were offline, so I did

3) select volume x (where x is the number of the offline volume)

4) online volume

So I could put all volumes again online and in fully working conditions.

What is the problem? On my next boot this morning the volumes were offline again. So something must be messed up.

I tried to make another new local account. Same story. I restored Windows to a previous known working snapshot. Same story.

Now when I put an external FAT32 HD into my USB port it is seen, if I detach my 1 TB HD drive and plug it in again, the volume is again offline and I have to do the diskpart again.

So the story becomes more interesting (sarcastically speaking). What and where has been messed up?

What I did before it happened. I installed two security updates for the .net., but I also have another Windows 8.1 on a VHD disk and did the same, and this installation is working without a hitch.

Besides, when I boot into the command prompt, all volumes are online.
 

My Computer

System One

  • OS
    Windows 8
Was a hard one. Well I've found the solution. One installation I did must have modified the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices\Offline changing all the values e.g. \DosDevices\C from 0 to 1, so effectively putting all volumes offline.

Changing back the values to 0 resolved the problem.
 

My Computer

System One

  • OS
    Windows 8
I'm having the same problem, even though I don't have a dual boot system. Can you tell me how to exactly do what you did? I mean, I accessed Mounted Devices but I don't know which values I should change when I open DosDevices\E , for example.
 

My Computer

System One

  • OS
    Windows 8.1
Double click on the \DosDevices\E and a window 'Edit DWORD Value' will pop up. Change the value data from 1 to 0 to make the drive accessible again.
 

My Computer

System One

  • OS
    Windows 8
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