Hub.BAT

The Hub.BAT is a program that when equipped into MegaMan's system complete's Hub's DNA within him. When he was created, Yuichiro Hikari as the first navi to incorporate human DNA to create a better bond with its NetOp, Hub's DNA was changed by 0.001% to prevent complete Full Synchro with Lan. Hub was Lan's identical twin brother who died shortly after birth meaning that they shared the same DNA. Yuichiro feared that if the DNA were the same in MegaMan, any damage received by MegaMan would affect Lan and vice-versa. When the Hub.BAT is added to MegaMan, the 0.001% difference is removed and MegaMan's code 100% in synch with Lan's DNA.

In MegaMan Battle Network, MegaMan had been severely damaged by MagicMan.EXE's life magic attack and Lan's father had sent Chaud with the Hub.BAT program in hopes of boosting MegaMan's power. After revealing the truth about MegaMan's creation, Lan reboots MegaMan with the Hub.BAT and MegaMan's programming gets rewritten strengthening his power, enough to defeat the Life Virus.

MegaMan Battle Network 3 presents Lan with Hub.BAT as a Navi Customizer Program that "brings out MegaMan's full potential". The program gives him over 15 abilities but causes a bug that halves his HP and always causes an error that needs to be modified no matter what style he is in.

Hub.BAT appears as a Giga Chip in MegaMan Battle Network 6 (Falzar version only) which works the same as the program above without the HP glitch.

Trivia

 * MegaMan and Lan gain the ability of full synchro starting in MegaMan Battle Network 4, alluding to the strong bond between the duo.