I've tried both of the above, but no luck. I've managed to get the ISO onto a datastore, I also have the ISO left on the external drive, which is connected to the computer that I use to connect to the server through vsphere client.
I powered on the VM, it starts to search for something to boot from but doesn't find, so I clicked the 'Connect to USB' button and navigated to the ISO on the external, but nothing happened - it still doesn't start to boot.
As this failed, I restarted the VM, to try to boot using the 'Connect to CD ROM' and navigate to the datastore where the ISO is. When I do this, the ISO is not found - the drive shows as empty. It can't be empty, because when I access the datastore from another virtual machine (which has the datastore added to it), I can see the ISO. Is the ISO maybe invisible because I have allocated the entire datastore to the other VM and that the datastore needs to be independent for the new VM to see files on it? Also, on top of this I noticed that when I click the 'Connect to USB' button, the VM is still trying to connect via USB from my previous attempt even though I have powered off the VM. How can I stop this process? I would have thought powering off would stop these processes.
Any other ideas why I may be having these problems? At this rate I am thinking of creating this VM in VM workstation and migrating it, but don't really want to have to do this out of principle as I have a new server with ESXi installed and want to learn to use it. It also takes along to time to migrate VM's.