Hi GraemePrentice
I am Dave, I will help you with this.
The best option is to use the free version of Macrium Reflect to perform the dick clone, Macrium is very reliable.
Then, when the cloning operation completes. boot into BIOS and set that 1TB drive as the primary boot device
Wait to test everything is working as expected.
Then, open Disk Management (accessible by ight clicking your Start Button)
Right click each partition on the old 500GB drive and select 'Delete Volume'
When the whole drive is marked as 'Unallocated Space' right click that and select 'New - Simple Volume' and accept the defaults
That drive will then be ready to use as a data (D) drive.