Windows build instructions

As VirtualBox is a cross platform project, we use a cross platform build system meaning that there won't be any Visual C++ project files that you can open and just build. Instead, you have to follow these steps but they aren't overly difficult.


  • Windows 7, Windows Vista, Windows Server 2003 or Windows XP SP3.
  • Visual Studio 2010 with service pack 1.
  • Qt v4.7.x or later
    Note! This has to be built with the Visual C++ compiler mentioned above.
  • code signing utilities (64-bit Windows only).
    Normally part of the WDK: certmgr.exe, makecert.exe, signtool.exe and so on.

Building VirtualBox

  1. Change to the root directory and execute our configure script to setup your build environment:
    cscript configure.vbs
    If the script finds all the tools necessary, it will output two files: AutoConfig.kmk containing information where to find the tools on your system and env.bat, a batch file to setup your environment for building VirtualBox. You only have to execute this step once, unless something about your tools changes in which case you have to repeat the above step. Keep in mind that the script always overwrites the two generated files so you should not manually edit them.
  1. Change to the root directory of the sources and enter our build shell environment: env.bat.
  1. To build a release package, type kmk. This produces the binaries in out\win.x86\release\bin. If you want to build a debug version, enter kmk KBUILD_TYPE=debug.

Using Visual C++ 2010 Express

If you don't have a Visual C++ license you can use  Visual C++ 2010 Express. However, you will not be able to build any frontend because the VirtualBox COM API - which all the other front ends program against - requires the Active Template Library (ATL) to build, and unfortunately the express edition doesn't include this (see

When doing the first build step, you have to add --with-VC-Express-Edition to the argument list:

cscript configure.vbs --with-VC-Express-Edition

Only for 64 bit builds: setting up self signing

Part 1: creating and installing the test certificate

  1. Launch an elevated command line shell (Vista and later).
  2. makecert.exe -r -pe -ss my -n "CN=MyTestCertificate" mytestcert.cer
  3. certmgr.exe -add mytestcert.cer -s -r localMachine root
  4. Start certmgr.exe and check that "MyTestCertificate" is listed both under "Personal" and "Trusted Root Certification Authorities".
    If you have a self-signed certificate installed and upgrade to Windows 10 it might happen that the certificate is still listed under "Trusted Root Certification Authorities" but not under "Personal" anymore. In that case, remove the old certificate using certmgr.msc and create a new certificate (see above) and install it.
  5. Keep the mytestcert.cer file in a safe place.

Part 2: configuring the system to run test signed code (Vista and later)

  1. Launch an elevated command line shell (Vista and later).
  2. Run Bcdedit.exe -set TESTSIGNING ON on an elevated cmd.exe prompt.
  3. certmgr.exe -add mytestcert.cer -s -r localMachine root
  4. certmgr.exe -add mytestcert.cer -s -r localMachine trustedpublisher
  5. Reboot.
  6. Vista: "Test Mode" will appear in all four corners of the desktop and "Microsoft (R) Windows (R) (Build 6000)" will appear on the top. Windows 7: "Test Mode<CR>Windows 7<CR>Build 7600" will appear in the lower right corner.

Part 3: building VirtualBox with signing enabled

  1. If you called the certificate something other than MyTestCertificate you'll have make the appropriate overrides in LocalConfig.kmk. See the Code Signing section of Config.kmk for what can be overridden.
  2. Add VBOX_SIGNING_MODE=test to LocalConfig.kmk.
  3. Build (incremental is sufficient).

Running VirtualBox

VirtualBox requires devices drivers and COM classes to operate. Whenever these change, you will have to re-register them. In order to re-register the COM classes, execute


which can be found in the output directory. Note that for this to work, VBoxSVC.exe must not be running, so use the Windows task manager to verify this. Usually VBoxSVC.exe terminates automatically after 5 seconds of inactivity (i.e. no client connection) but especially when developing, it might sometimes stay around. In case the COM classes change (this usually happens when the file VirtualBox.xidl is updated) and you forget to re-register the classes, weird problems may appear.

In order to (re-)install the VirtualBox kernel drivers, issue the following:


Starting VirtualBox is accomplished by invoking one of its frontends, such as



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