imac 2012 not booting

[matthewbryan]

my first post
my iMac running el captains started flashing and the dockat the bottom disappeared so i decided to use a restore point. There was a power failure part way through and now the all i get is


os x could not be installed on your computer

volume contains an os x installation which may be damaged

quit the installer to restart your computer and try again







i only ever get as far as this point .......Helpppppp

 

[Cory Cooper]

Hello and welcome.

-What do you mean by "so i decided to use a restore point"? Time Machine?

This issue could be difficult to remedy via this forum, without being able to see the machine in person. Do you have an Apple Store near you that could help out?

C