recovery disc

why does dell write there recovery software aka windows. to if you get a system with a 1 TB HDD per say. then that's all you can reinstall into it is another 1TB HDD or SSD. and they won't let you create partitions. the computer will just throw a fit that your not reinstalling another drive of the same size that came with the unit when it was shipped. one reason i would not buy anther dell again there to propritary for me