I mount an ISO image with the button at the top, but when I restart the virtual machine it disconnects. This makes it really tricky to get a CD mounted to boot from it. I have to hit F8, then mount the ISO, then select CD-Rom from the list, otherwise I don't have time.
Is there an option to disable dismounting of ISO images on reboots of VM'S?
Best help I can give is make it so it boots from cd-rom
Power up your guest, and hit f2 (if you miss first time hit reset)
change the boot sequence in the bios to cd-rom first.
Not much help, you are doing it the right way. But on the plus side, once you have your OS, you can clone from this so will only need to get it right once.
This appears to be normal behaviour. The only other possible advice I could give you would be to create a lun for your iso images or store your iso's somewhere in your datastore. This way when you select your Datastore ISO in the VM's settings they wont disconnect when you reboot!
Otherwise the method you are using is probably the best to stop the machine booting up, mount the iso and continue from there!