Fixing the error "Could not open session for virtual machine"

Currently, virtualization programs are becoming increasingly popular. They allow you to use some parts and resources to run one operating system inside another. This technology is practically a necessity for users of Windows 10, as many useful programs and utilities are compatible only with older versions of the OS from Microsoft. The most advanced virtual machine at the moment - VirtualBox. In general, it is very easy to use and stable, unlike its predecessors. However, it is not without periodic problems and errors. The most frequent of them is “Could not open session for virtual machine”. It can occur both when installing software, and when used repeatedly. What is the problem and how to solve the problem? Let's start in order.

What to do if the error “Failed to open the session for the virtual machine”.

The essence of the problem

The error with code 0x80004005 can be found on all relatively new versions of the “Windows” from 7 to 10. It is also not connected with the VirtualBox version. In other words, the virtual machine cannot run the OS image. This can happen even if the user has successfully installed and configured the program. Attempting to solve the restart problem will not succeed. What then can be done?

Method 1

  1. Open any file manager ("Explorer" or "Total Commander").
  2. We go to the C drive (well, or to the system drive, if you have it indicated by another letter).
  3. Find the folder "Users" (or "Users").
  4. Next we need a folder with account data.
  5. We are looking for "VirtualBoxVMs". In it we open the virtual machine directory.
  6. There will be three files with the names of the OS image (for example, Windows 7). Copy them to any other place.
  7. Next, go back to the directory to the original files and delete the Winvbox. Win7.vbox-prev renamed to Win7.vbox.

TIP. in some operating systems, it may be called Win7.xml or Win7.vbox.

In most cases, this simple procedure works. If not, go to the second method.

Method 2

Also, the cause of a malfunction may be a newly installed Windows update. As we already said, automatic updates can cause malfunctions in the programs. In this case, the solution may be to delete all the latest installed updates or a specific one (usually the “culprit” is an update with the code KB3004394). The removal process we have already described in detail. This can be done by several methods. Recall the action through the command line.

  1. Click "Run" in the "Start" menu.
  2. Type cmd and click OK.
  3. Enter the command to remove the update we need: wusa / uninstall / kb: 3004394
  4. Press Enter.

If the system finds the file, it will delete. If not, you can try to get rid of all the latest automatically installed. It happens that the system does not find the necessary update, and, accordingly, can not fix the problem. In this case, go to the next method.

Method 3

If none of the above solutions did not help and the error is still highlighted, you should resort to installing another version of VirualBox. The official site has a list of the most stable variations. Your task is to replace one with the other with the preservation of data. We act as follows:

  1. Go to the menu "Add or Remove Programs" on the Control Panel.
  2. We find there VirtualBox.
  3. When deleting, the application will ask for permission to delete user data. Click "No".
  4. Install another version from the list.
TIP. In some cases, the older version may be incompatible with OSes. Then you have to uninstall the application with all the data, and only then install another version.

Note that during the installation, the Internet connection may be lost. Normal restarting the computer will fix the problem.

Method 4

You can also resolve the problem by forcing the hyper-visualization off. Note that this method will not work on 32-bit OS. If you have a 64-bit device, do the following:

    1. Go to the "Control Panel".
    2. Select the item "Programs and components."
  1. Click "Enable Windows Components".
  2. In the opened tab, remove the check mark from «Hyper-V».
  3. Reboot the PC.

We considered the most popular and practical methods for eliminating errors. As a rule, one of the proposed options should work and restore the work of the virtual machine. If not, describe your problem in the comments and suggest other ways out of the situation.