Reinstalling OS X without Apple ID

[claudiall]

Hi,
I've a huge problem. I have an old imac (over 10 years old) from work with El Capitan. It's having trouble booting up, it turns itself off during the apple logo load screen. So I decided to wipe the drive. I turned it on pressing cmd+R, accessed disk utility, backed up all my files, then wiped the disk clean. But when I tried to reinstall the OS, it asked for Apple ID and password. It has to be the one used on the computer, but the former employee hasn't been heard of in years, nobody knows which ID was used, and it won't accept mine.
I can't reinstall from a CD cos we removed the CD drive years ago to make room for a larger memory.
The model is too old for shift+alt+cmd+R to work (we tried)
I heard you could reinstall from a flash drive, but I didn't understand the step by step. What can I do at this point? I need this for work (I'm a designer) and I'm completely stuck!

 

[Cory Cooper]

Hello and welcome.

• Which exact model iMac?
• You can create an installer flash drive, using these resources:
  • How to download and install macOS
  • Create a bootable installer for macOS
• Does your company have an IT department?
• Do you have an Apple Store close to you - sometimes they can reinstall macOS for you

C