RE: Dell diagnostics error code 0F00:0240
Error code: OFOO244, uncorrectable data error or media is write protected, means the hard drive is toast and needs to be replaced.
Dell made many different Inspiron laptop and desktop models, what is your model and the version of windows that's installed?
"Did have time to create a back up on the alternative disk of the state when it was working last night so... HOW DO I ACCESS THAT TO BOOT IT?"
I have no idea what this means, please post more details.
Did you create a bootable disk?