unable to clear hard drive

[chickade]

Hello. Thanks in advance for this forum. I have a mid 2011 imac with High Sierra. It was contaminated by Clean My Mac. I want to totally clear the hard drive but nothing I've tried has worked. I made a High Sierra bootable USB using the terminal window but that was not recognized for the installation. The computer is useless with the Clean my Mac present. I tried all the key combinations for recovery mode but the usb drive was not offered as a source of installation for any of them.

 

[velocityg4]

Did you just try using the Option key? It needs to be held before the chime and I keep it down until the disks show up. At least with USB keyboards.

Although I don't know if this is true for all Macs. My iMac when using a bluetooth keyboard. I have to wait until the chime to press the option key. Making sure to press it during the chime. Keeping it held down until the drives show up. It won't recognize the input from bluetooth if pressed before the chime.

By the way for High Sierra. If you get the installer to load. It may not install because of a date issue. With the following.
Installation Failed An error occurred while preparing the installation. Try running again.

Disconnect from WiFi or Ethernet first
Open Terminal

date 1220122018

 

[chickade]

Thanks for your note. I tried the option key after turning on, but I did not try holding it down after the chime. I will try that next.

 

[velocityg4]

Thanks for your note. I tried the option key after turning on, but I did not try holding it down after the chime. I will try that next.

During the chime is what I shoot for or immediately after. Try both ways.