"100mb showing on adapter properties"
The typical reasons are : -
1. The driver of the computer is set to 100 full duplex - remedy make sure 1Gb/s exists on the list but select Auto.
2. The computer is connected to a 10/100 device like a Basic Network Switch / AV600 Powerline Adaptor / a WiFi Extender - 10/100 is the max in this case.
3. The computer is direct connected to the Hub ( 1Gb/s <--> 1Gb/s ) but an out of spec or defective network cable is de-rating the link from 1000 to 100,
in this situation a new network cable e.g. CAT6A or better is the remedy.