I have done the following:
Quick Defrag, Normal Defrag, Boot Time Defrag and Defrag Free Space. There are still 4 blocks in the middle of the hard drive that will not move. See image.
How can I move these blocks please?
Sometimes it's just like that and they can't be moved, or Windows won't let them be moved.
Especialy with the Operating System disc which is what you are showing there.
TBH it doesn't make any difference, modern discs are fast enough that loading times won't be affected by more than a millisecond or so.
And you have plenty of freespace there.
PS. You may have noticed that the Windows built in Defregmenter/Optimiser no longer shows a drive map like that, that's partly to stop people wasting their time trying to achieve the 'Holy Grail' of a solid block of blue squares at the start, it's hardly ever achieveable except perhaps with a brand new disc. (or possibly a non-OS drive formated as FAT/FAT32/exFAT).