• Poor performance with 32-bit guests on AMD CPUs. This affects mainly Windows and Solaris guests, but possibly also some Linux kernel revisions. Partially solved in 3.0.6 for 32 bits Windows NT, 2000, XP and 2003 guests. Requires 3.0.6 or higher Guest Additions to be installed.

• Poor performance with 32-bit guests on certain Intel CPU models that do not include virtual APIC hardware optimization support. This affects mainly Windows and Solaris guests, but possibly also some Linux kernel revisions. Partially solved in 3.0.12 for 32 bits Windows NT, 2000, XP and 2003 guests. Requires 3.0.12 or higher Guest Additions to be installed. • NX (no execute, data execution prevention) only works for guests running on 64-bit hosts or guests running on 32-bit hosts with PAE enabled and requires that hardware virtualization be enabled. • For basic Direct3D support in Windows guests to work, the Guest Additions must be installed in Windows 'safe mode'. Press F8 when the Windows guest is booting and select 'Safe mode', then install the Guest Additions.

You can either install El Capitan over your current version of OS X, not disrupting your programs/data, or you can perform a clean install. A clean install will offer you significant benefits over running the automatic upgrade procedure, as it gives your Mac a complete new fresh state. Malwarebytes for mac os x el capitan.

The included vbox guest additions certificate is expired: $ keytool -printcert -file oracle-cert.cer Owner: CN=Oracle Corporation, OU=VirtualBox, OU=Digital ID Class 3 - Microsoft Software Validation v2, O=Oracle Corporation, L=Redwood S.

Otherwise Windows' file protection mechanism will interfere with the replacement DLLs installed by VirtualBox and keep restoring the original Windows system DLLs. Note This does not apply to the WDDM Direct3D video driver available for Vista and Windows 7 guests shipped with VirtualBox 4.1. • Guest control. On Windows guests, a process lauched via the guest control execute support will not be able to display a graphical user interface unless the user account under which it is running is currently logged in and has a desktop session. Also, to use accounts without or with an empty password, the guest's group policy must be changed. To do so, open the group policy editor on the command line by typing gpedit.msc, open the key Computer Configuration Windows Settings Security Settings Local Policies Security Options and change the value of Accounts: Limit local account use of blank passwords to console logon only to Disabled.

• Compacting virtual disk images is limited to VDI files. The VBoxManage modifyhd --compact command is currently only implemented for VDI files. At the moment the only way to optimize the size of a virtual disk images in other formats (VMDK, VHD) is to clone the image and then use the cloned image in the VM configuration. • OVF import/export. • OVF localization (multiple languages in one OVF file) is not yet supported. • Some OVF sections like StartupSection, DeploymentOptionSection and InstallSection are ignored.

• OVF environment documents, including their property sections and appliance configuration with ISO images, are not yet supported. • Remote files via HTTP or other mechanisms are not yet supported. • Neither scale mode nor seamless mode work correctly with guests using OpenGL 3D features (such as with compiz-enabled window managers). • The RDP server in the VirtualBox extension pack supports only audio streams in format 22.05kHz stereo 16 bit.

If the RDP client requests any other audio format there will be no audio. • Preserving the aspect ratio in scale mode works only on Windows hosts and on Mac OS X hosts. • On Mac OS X hosts, the following features are not yet implemented. • Mac OS X guests can only run on a certain host hardware. For details about license and host hardware limitations, please see and check the Apple software license conditions. • VirtualBox does not provide Guest Additions for Mac OS X at this time.

• The graphics resolution currently defaults to 1024x768 as Mac OS X falls back to the built-in EFI display support. See for more information on how to change EFI video modes. • Mac OS X guests only work with one CPU assigned to the VM. Support for SMP will be provided in a future release. • Depending on your system and version of Mac OS X, you might experience guest hangs after some time. This can be fixed by turning off energy saving (set timeout to 'Never') in the system preferences.