Q: How do I install the update if I cant get by the frozen start up screen? Can I start it in safe mode and upgrade from there somehow?

The header says most of it. Just let me know if it's possible to fix this on my own or if I need to take my Imac over to a specialist tomorrow.

My Imac froze as I was trying to pull a photo from Safari into indesign (and the entire screen way overlaid by a weird screen filter – white and grey squares like the opace background in photoshop) about an hour ago. I used the power button to shut it off. Unplugged everything and waited a while.

Now when I start it I have horizontal lines on the first startup screen (together with the apple and the wheel). Then it changes to a normal white screen and then freezes at the blue screen. I'm unable to get further.

Thanks!