On 4/22/23 10:30, mick.crane wrote:
I suspect the GPU is suspect because there are small blocks of pixels appearing where they aren't wanted.I'd like to re-install the OS as I've got copies of everything I think. Just to see if it's maybe a driver issue.Thing is I can't get the f12 options screen of the PC to let me boot from a CD in this EFI mode what's grub done.How can I boot from CD in this EFI mode? mick
Without knowing the make and model of the computer, it is difficult to offer specific advice.
When you power up the computer, there should be a hot key to enter the System Setup utility (or whatever it is called on your computer). Press it. Then find whatever screen(s) are used to enable boot device(s). You may need to create an entry for the optical drive and/or enable booting from the optical drive.
David