OSX Yosemite 10.10.3 freeze during installation now won't start up help!

My experience with this:

I just updates a server to 10.10.3 via ARD and entered slight panic mode seeing the spinning beach ball.at about 4 minutes left and no progress going on. Which brought me to this topic.

Since I'm not on the premise and really didn't want to deal with Safe Boot etc. especially at 1am local time. I tried SSHing into the box which worked just fine, I did a process status (ps aux) to see whats not going but saw nothing out of the ordinary.

So I went back into ARD and found myself back at the Desktop with the update to 10.10.3 completed.

So my personal advise:

Give it time, try to find out whats really happening before doing anything very time consuming :-)

It wouldn't be the first time some update/upgrade from Apple lets you wait 30mins to 2 hours before showing progress.

The steps you laid out helped me a lot. Thanks krijnpalm!

I Have updated my computer to XS O Yosemite. When I have clicked onto the app to install it, the computer started the process to update and it has frozen when it restarted and will not let me do anything. I turned the laptop off and when I turn it back on it freezes at the same point. All I can see is the apple sign half loaded with the spinning ball. Can anyone help?

I Held the shift key when I first turned it on but nothing has happened and it has frozen on the same part again.

thank you

I was having this issue as well. Now when I power it on and get to the installation screen, after about 10 seconds it gets to about half way and the screen goes black. It doesn't shut the whole way off but I can't get anything on the screen go appear. Any advice?

**I already repaired the HD. If I try to power into safe mode, it sits on the loading screen for hours. (7 hours yesterday)