Well the 100MB partition is the System Reserve parttition.
MS doesn't like ppl messing with it.
Win 7 should have a 100MB System Reserve partition, Win 8.1 and 10 should have about 300-400MB System Reserve partition.
If it were me, I would back up any data you want to save, and make sure you have the exact make/model of the lapto.
Download the drivers for the laptop, and put them on a USB stick or CD, and then wipe the whole drive and do a clean install of Win 10.
/e You can use AIDA64 Extreme to get the "true" Windows CD key from the laptop, before you delete all the partitions and format it.
This post was edited by Ghot on Aug 9 2016 03:13pm