Thank you. I will take a look at those.
I guess I was using the wrong language by calling it "recovery partition". Yes, it is that "sysem reserved" partition that I want back.
My disk management does not show any 100MB partition, but an 8.98 GB unallocated partition. That is perhaps the Lenovo recovery partition, or their "Quickstart" thing, or maybe just empty space.
In any case, I will take a look at those tutorials. Thank you.