It won't even let me back up my start up disk with disk utility to an external hard drive. So my question is how to I delete the partition to start over.
27 inch imac
Use Boot Camp to remove the partition, at the download drivers page select I have the disc, continue to create or remove a windows partition and remove it.
I tried that at first but an error message pops up that says
The start up disk cannot be partitioned or restored to a single partition
The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.
I really don't know what happened
That message has been discussed many times in the Boot Camp forum. You might want to head over there. It is where the Boot Camp Gurus hang out. https://discussions.apple.com/community/windows_software/boot_camp
You said you were trying to remove the partition ("So my question is how to I delete the partition to start over"), so I gave you instructions how to do that,
This
"The start up disk cannot be partitioned or restored to a single partition
The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows."
Is a whole different issue and has been covered on this site 1 million times, search for it.
While trying to use bootcamp, I got a blackscreen, now I'm trying to delete the partition but it isn't working.
