is my mac completely fried?

[Flower140]

so i got this (pretty old) mac from a thrift store about a year ago. when we got it we had it fixed at a local electronics repair store. well since i’ve been getting pop ups about how my free trial for this ad blocking software ran out. i’ve never gave it to the membership because we already spent a good amount getting it fixed and it was just pop ups anyways. tonight i found out that’s a money scam and i should get rid of it. so i did. then i went to try and clean my mac as i’ve had other problems as well. such as browser hijacking… i see something called install OS el captain and i looked up this application and everything said it was safe so i click and install..idk it didn’t look suspicious…wellll now i’m here. my computer won’t boot up and i’m getting weird dots. can i fix it or is it beyond repair?

 

[MarkC426]

Maybe a bit more computer spec info....?

 

[MBAir2010]

have we tried time machine back up to restore the mac?
that procedure always works!

 

[MacCheetah3]

Do you have any important data on it (yet)?

If not, I recommend going right to a reinstall.

How to reinstall macOS - Apple Support

Use macOS Recovery, your computer’s built-in recovery system, to reinstall the Mac operating system.

support.apple.com

(Use Intel Mac instructions)

 

[Hombre53]

Be sure to format the disk using disk utility before doing the re-install of macOS. This assumes you have a backup right?

 

[hobowankenobi]

Sorry to say screen artifacts are often hardware.

Booting to a different OS (external, Recovery mode, etc.) is a quick way to see if it the issue remains (likely hardware), or goes away (likely OS).