Blu-ray discs don't play natively in Windows 8, and as a result you'll have to install software to play blu-ray discs if you have a blu-ray drive connected to your Windows 8 system. Below are instructions on how to setup VLC (aka VideoLAN) for free blu-ray disc playback. There are instructions on how to do this scattered across the Internet, but they tend to leave a few things out as well as not clarify what versions you need under certain system configurations.

If you are using the 64-bit Windows 8 OS then download and install the 64-bit version of VLC:
Index of /pub/videolan/vlc/last/win64/

If you are using the 32-bit Windows 8 OS then download and install the 32-bit version of VLC:
Download VLC media player from SourceForge.net

(Using the 32-bit VLC software to playback blu-ray on the 64-bit OS doesn't work at the time of this posting).

Hold down the Windows key and press R to open the Run window. In the run window type: %appdata%
In the directory that opens create a new folder titled: aacs
go to the VLC Blu-Ray website
Download the KEYDB.cfg file and save it in the aacs folder you created earlier

If you are running the 64-bit Windows 8 OS then download the 64-bit libaacs.dll file
and save it in the in the VLC directory.
(On my system that's E:\Program Files\VideoLAN\VLC because I have an ssd and hdd, and I installed the 64-bit VLC to my hard drive which is E:\. For most people it would be C:\Program Files\VideoLAN\VLC)

If you are running the 32-bit Windows 8 OS then download the 32-bit libaacs.dll file
and save it in the VLC directory.
(For most people this will be C:\Program Files (x86)\VideoLAN\VLC).

Now launch VLC, select the Media tab, Open Disc, click the blu-ray button and your blu-ray (assuming you put the disc in your drive ) (Leave No Menu checked - currently VLC blu-ray playback doesn't support menus).

If your video loads up with menu bars at the top or bottom (or it opens two video windows) then right click on the video, select Video , then change Video track from Track 2 to disabled. The video window will close, but the VLC media player window will still be open and displayed. On that window click on the video tab, select Video Track, and then select Track 1. Double-click on the video, and your blu-ray video should be running full screen. (Hopefully VLC will patch the video track bugs).

There you go free blu-ray disc playback.

Source: http://forum.notebookreview.com/windows-os-software/699817-playing-blu-ray-discs-windows-8-using-vlc-media-player.html

Below is a comment for playing Blue Ray discs using DVDFab...

I do not run Windows 8 but I have run into problems playing some newer Blu-ray movies on Window 7, mainly because Blu-ray constantly changes their encryption so that you have to have the latest firmware installed on your BD combo drive or BD writer that is installed in your PC, and sometimes you even have to upgrade to the latest playing software as well just for the privileged of playing a movie that you have paid at least 25 dollars for. So what do you do if you have a blu-ray drive that the manufacturer does not issue firmware updates, like on my laptop? VLC is a great media player however it will not play encrypted blu-ray movies because being free they do not have any of the encryption algorithms installed. A solution that I found to be great at least for me was a program that is called Passkey for Blu-ray and DVD that is put out by DVDFab.com. Passkey is a driver that runs in the background and automatically decrypts any disk put into your BD drive and then sends an unencrypted stream to your player software in real time. They also make a wide range of other video related software that you might want to check out, a couple that come to mind is movie creation software as well as BD ripping software, and software for creating MKV files. Oh I forgot to mention that they have a subscription service for Blu-ray Passkey where you can pay for it to work for 2 years for 59 dollars, however the lifetime license is currently on sale for 105 dollars and is available for Widows including Windows 8 as well as the Mac. I bought this a couple of months ago when it was on sale. In that time they have issued several updates. Now I can use my favorite media player VLC to play anything including Blu-ray movies. I also have their Blu-ray ripping software and have been creating HD MKV files from my collection of Blu-ray and DVD movies and putting them on my NAS media server that I built using FreeNAS running on an NAS raid using an old server case and the new WD Red drives.

Source: http://www.makeuseof.com/tag/why-wont-windows-play-my-dvd-or-blu-ray-disc/#comments