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My host is WinXP SP3, and I have 2 VMs, one Ubuntu and the other WinXP SP2. Everything was shut down last night when I went to bed. This morning, the WinXP VM was showing inaccessible. Everything is greyed out except for the refresh button that does nothing. No access to 'Settings' or anything else. How to I get it back instead of creating another one. The VDI file is still there.

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Official VirtualBox forums (where you're more likely to find help quickly) are at: – Brian Knoblauch Jan 4 '10 at 13:20
Add your comment as an answer - it may get accepted. You never know. – cometbill Jan 4 '10 at 14:33
More precisely, on Windows check the %USERPROFILE%\.VirtualBox\HardDisks folder. – Goyuix Jan 4 '10 at 15:55
up vote 2 down vote accepted

Worse comes to worst, locate the VDI file that represents your virtual hard disk, and create a new VM using that as your hard drive. You'll lose any snapshots, of course.

The default directory for VDI files is c:\documents and settungs\\application data.virtualbox\HardDisks, I believe. (I use a Linux host and don't currently have a Windows-hosting box to check.)

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if the reason is indeed the newly installed version of VirtualBox, then old VDIs and snapshots simply do not work. – Molly7244 Jan 4 '10 at 16:04
CarlF wins the jackpot. Am writing this from the VM now. So I guess it wasn't the newly installed version of VB. Thanks all. – funbi_grace Jan 4 '10 at 16:59
To Molly: I've used VirtualBox for some time and never actually had an "incompatible format" problem on upgrades. Has that ever been a real problem? – CarlF Jan 5 '10 at 4:48
Is it possible to access the virtual machine's files if the virtual machine can't be booted? One of my virtual machines in now inaccessible, and I have a couple of important files stored there. – Anderson Green Nov 16 '12 at 20:35
@AndersonGreen, you can create a new VM (using Linux as the guest OS if you don't have a spare Windows license) and mount the virtual machine's HD as a second hard disk. Takes maybe 15 minutes on a reasonably fast PC. You can directly mount the virtual disks but I'm lazy and never learned how. – CarlF Nov 28 '12 at 18:41

the information is stored in XML files, are they still there?

check c:\documents and settungs\<user>\application data\.virtualbox\machines

did you receive an automatic update? sometimes new versions render old virtual machines useless, in this case uninstall virtualbox, reinstall the older version and disable automatic update.

older versions can be obtained from

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Directory is still there with Logs directory and the xml file. hm. I installed the latest version of VB over the old one, and although I can't say for sure, I think I have restarted the VM a couple of time since then. It's worth a try to go back to the older version. Will revert. – funbi_grace Jan 4 '10 at 15:08

It happened to me to day, I shutdown a guest operating system, and the virtual box manager told be that it was not accessible.

Luckily I just closed the manager and restarted it and all was well.

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This has worked for me in many occassions:

  1. Pay attention to the error as to why it is inaccessible (sort of "can't find uuid={e973ec45-4137-4120-8052-ccb641c8f5e6}")

  2. Locate the .vbox file in your VM folder (right click --> Show in Explorer)

  3. Edit this file (e.g.: VIRTUAL1.vbox) using Wordpad (don't use NOTEPAD for this, as it won't handle the UNIX style lines in a proper manner!)

  4. Close VirtualBox

  5. Within the opened file, locate the reference to the complex string (e.g. {e973ec45-4137-4120-8052-ccb641c8f5e6}) reported in 1., it'll usually be between delimiters such as these:

    <AttachedDevice type="HardDisk" port="1" device="0">
      <Image uuid="{e973ec45-4137-4120-8052-ccb641c8f5e6}"/>
  6. Delete the whole 3 lines above (just save a copy of the unmodified file first) and save the file. What you've done here is delete a reference to a snapshot which is the cause of the trouble.

  7. Open VirtualBox again; your Inaccessible VM should now be accessible.

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A broken solution:

Call me old fashioned but should software should work - in this case by supporting backwards compatibility?

Shutting down virtualbox, copying the xxx.xml file to, adding the xxx.vdi file through the Virtual media manager, in file browser double click xxx.vbox file to register vm.

This works till a point where the VM's created this way work and suddenly become inaccessible.

I did delete the add new network adapters, which are directly associated with the machine and not the VM.

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