Deleting Windows 8.1 Pro

I've tried deleting it the "proper way". Through system recovery. Every time it says "some require files missing. Please insert disk". Well I don't have the disk. I can find no other way to delete windows off my computer. This 8.1 is an absolute joke. I have to get it off my computer. Any other options? Someone suggested deleteing the partition but I cannot find any online tutorials on how to do that as I am not an expert.