Enable 3D Acceleration & Windows Aero in VirtualBox - Guide

Enabling 3D Acceleration in VirtualBox for Windows 7
VirtualBox offers an experimental feature for 3D acceleration, which facilitates the utilization of the Windows 7 Aero interface within a virtual machine environment.
Furthermore, this capability extends to running older 3D games directly inside the virtual machine; however, performance with more recent titles is likely to be suboptimal.
Activating Aero After Windows 7 Installation
Users who have installed Windows 7 using VirtualBox may initially encounter the Windows 7 Basic interface. This can be a source of disappointment for those expecting the Aero experience.
Fortunately, Aero can be enabled through a series of straightforward adjustments.
These adjustments allow for a more visually rich and familiar Windows 7 experience within the virtualized environment.
It’s important to note that 3D acceleration is still considered experimental, so results may vary depending on your system configuration and the specific virtual machine settings.
Configuring Virtual Machine Parameters
Before modifying the configuration of your Windows 7 virtual machine, ensure it is completely shut down. Altering settings is impossible while the virtual machine is running or in a suspended state.
To access the settings, locate the virtual machine in the VirtualBox Manager and right-click on it. Then, choose "Settings" from the context menu.

Navigate to the "Display" section within the settings window. Activate the "Enable 3D Acceleration" option by checking the corresponding box.
Furthermore, adjust the video memory allocation using the slider. A minimum of 128 MB is required, but 256 MB is recommended if you intend to utilize multiple monitors within the virtual machine environment.
While not essential, enabling "Enable 2D Video Acceleration" can improve performance for applications that rely on 2D overlays during video playback.

Installing 3D Drivers in VirtualBox
Following the configuration of the previously discussed settings, confirm your choices by clicking OK. Subsequently, initiate the virtual machine by performing a double-click on its icon.
With the virtual machine now operational, navigate to the Devices menu and select the option to Install Guest Additions.

Within the AutoPlay window that appears, choose the Run option to begin the installation process.

Advance through the installation wizard until you encounter the Choose Components screen. At this point, select the checkbox labeled Direct3D Support (Experimental).

A prompt may appear asking if you prefer to install the basic Direct3D support. Select No to proceed with the installation of the WDDM driver, which provides compatibility with Windows Aero.
Should you opt for the basic Direct3D driver, installation requires booting into safe mode. Restart the virtual machine and press F8 during startup to access Safe Mode, then install the Guest Additions from within that environment. Keep in mind that the basic driver lacks Aero support, but is considered potentially more stable. However, the experimental driver has proven reliable in our testing.

VirtualBox will display a warning indicating a minimum requirement of 128 MB of video memory. This amount should have been configured in a previous step. If not, the virtual machine settings can be adjusted following driver installation.

Initiate the installation by clicking Install. VirtualBox will then install the Guest Additions and the experimental 3D driver within the virtual machine. A system restart will be required upon completion of the driver installation.
Activating Windows Aero
With 3D support now integrated into your virtual machine, you are able to run legacy 3D games and utilize applications demanding 3D acceleration capabilities.
By default, however, Windows Aero remains disabled. To activate Windows Aero, a simple right-click on the desktop of your virtual machine is required, followed by selecting the "Personalize" option.

The currently applied theme is typically Windows 7 Basic, which does not incorporate Aero features. Within the Personalization window, navigate upwards and choose an Aero-enabled theme, such as the standard Windows 7 theme.
Selecting an Aero theme will automatically enable the Aero visual style.

It’s important to remember that 3D acceleration and its associated driver are considered experimental within VirtualBox. Should you experience instability or other problems, consider disabling 3D acceleration and removing the driver to restore a more stable virtual machine environment.