The 10.89 GB partition contains the restore image for your C: drive and is hidden from your operating system to help prevent accidental damage to it. It is generated by Dell at the time your system is built, but they don't keep a record of it. Once you have removed it you cannot replace it. Microsoft has nothing to do with it.
I'm not certain about Windows 7, but with Vista the image was produced by something called imageX or some name similar to that. Datasafe won't touch it.