You may want to reset BIOS.  Unplug power, remove coin-cell batt, holding power button for 15 sec., re-install batt (put in a fresh, new one if you want).  Power on the machine, system may cycle through a few times.  Use F12 to prevent Windows boot (error), select BIOS setup and make change accordingly to how you want your system to be.

Hey ho' easy peasy.  

Thanks for the advice.

No, didn't work.

It only boots in legacy mode.  I have to F12 then choose the hard drive to boot.

Ok, the UEFI radio button has come back in the boot list option section, however I now have two windows boot manager tick boxes in the Boot Sequence section.  No UEFI Tick box.

Further info:  With the UEFI radio button is checked in the "Boot List Option" section, I click on the "Add Boot Option" button, I get the reply File system not found.

Click on the "View" button, I get three windows "Boot option name", "File system list" and "File Name". In File name is: \EFI\BOOT\Bootx64.EFI  Could this file be missing, and from where?

Thank you fort your help.

Sorted.

The file that was deleted in the bios set up, was in Windows.

I changed the hard drive, reinstalled Win 7 no problems. Runs like a dream.

Phew, I won't be doin that again.