Realtek's free High Definition Audio Codec pack enables stereo digital audio at resolutions up to 24-bit/192kHz, as well as 5.1-channel Dolby Digital audio. Though it's essentially a package of drivers, it installs like a Windows program and may require a reboot. Realtek HD Audio Codec is available in separate downloads for 32-bit or 64-bit Windows Vista, 7, and 8 systems with Realtek controllers.

Pros

Audiophile-quality digital audio: No matter the source, you'll get super-high-quality digital audio. We streamed audio at up to 320kbs from Spotify and other sources. Even MP3s sounded better.

Dolby HT4: Dolby Home Theater 4 settings include Movie, Music, and Game modes with up to six presets, or you can turn Dolby off in the Properties dialog.

Multiple output options: We could select and configure Realtek Digital Output options for all our digital connections and output jacks, including optical, USB, and internal ATAPI.

Cons

Realtek HD controllers only: Not all motherboards use Realtek audio chips, and not all Realtek controllers are HD-compatible. Fortunately, the codecs won't install on the wrong system.

Watch the installation: There are other programs added automatically during the standard installation. Choosing the Custom installation option let us decline "extras" we didn't want.

System compatibility: While Realtek HD Audio Codec works with Realtek controllers, some motherboard implementations may not be fully compatible and require proprietary audio drivers instead.

Bottom line

If your PC has a Realtek HD audio controller, Realtek High Definition Audio Codec will help you get the most out of it. Chances are, your Realtek controller may already have this codec, courtesy of Windows Update. If it doesn't have it, get it!