Part of Container disk locked, how can I access ?

[freddy]

Long story short, I am a newb.

My Apple Mail did`t work, so I tried to re install Mac High Sierra, it said failed.

Ended up with a new desktop and all files gone, I miss them badly !

I can see they are still there, but I can not reach them, Anyone who can help me with this ?

Hope for some help, thanks

 

[Lufbrarunner]

Which model Mac?
How did you re install High Sierra?
Do you have any backups?

 

[freddy]

Which model Mac?
How did you re install High Sierra?
Do you have any backups?

Thanks for comment.

It is a Imac from 2011
I restrted the mac with "alt" and I could choose from "Machintosh disk" or "Installer" I choose I"nstaller" but it kept saying failed when trying to re-instal the High Sierra, so after that I choose "Machintosh"

It seems like it overwrote the exciting data and made a new start with the remaining GB

I dont have a backup.