I did preorder… but the install button is disabled in BattleNet…
Is there an extra step?
I thought nothing special was required on PC+BattleNet?
And the beta download starts March 15 9AM PDT (they say)
Your Guide to the Diablo IV Open Beta — Diablo IV — Blizzard News
Click on the Diablo IV- Beta not the D4 game
Ooooo… there is a “D4 beta” game! 
Oopsie, now I see it, it’s the game version. Was not available before, new (beta) version!
Thanks matey! 
No problem. I did the same thing.
Yar.
The drop down menu over the main “Play/Install” button has the game versions. Select Beta then it should start the download.
Mine is done now. Did not take too long.
It’s 3am here… but couldn’t sleep haha…
And it just so happens I have 2 weeks holiday between jobs starting today, lucky me! 
https://i.imgur.com/1asB6PU.png
Those of you that may not see the drop down, be sure to log out, close your launcher, then restart and log back in. It should then show, providing you pre-purchased or were given a beta code. It may be available to everyone for all I know, but not playable by anyone other than those with pre-purchase or key access - That’s the next beta weekend that anyone can get in to play, whether they bought it or not.
Also those of you with limited internet speed or drive space, before installing, you can customize the install and cut the download size in half by not installing the high res textures.
80 GB here we go!
Looking forward to playing the beta.
Took about 45 minutes at 35-40 MBs/s (not Mbs/s) no probs.
Thank you. This solved the problem.
Geez 85 gigs. I gotta delete some sh*t
You can cut it down to 45gig for non high resolution.
What are the high res assets for? If I play on low settings, I won’t need them?
It’s has stuck on the last 80.00kB for about 20 minutes.
WTF?
Edit: I restarted Battlenet and it’s ok.
I wouldn’t think so, but im not certain. I know its playable but probably without the high resolution graphics.
I deleted AC Odessey. That freed up 70 gigs. D4 beta’s final size turned out to be 77.3 GB
Still isn’t showing for me. Pre-ordered the Ultimate edition back in December. My launcher shows that I’ve purchased the game, but the drop down only has the live version. I’ve tried logging out of the launcher, closing it, opening it, logging back in, and that didn’t work. Also tried rebooting my PC.
Possibly update launcher?