List of Mega Man Battle Network 4 upgrades

List of Upgrades from MegaMan Battle Network 4 and their location

HP Memory
HP Memory increases a NetNavi's max HP (Hit Points). It increases a Navi's HP by 20. In each game there are 45 HP Memories (in total raise a Navi's HP by 900) giving MegaMan a base maximum of 1000 HP.

Sub Chip Memory
Introduced alongside the concept of Sub Chips in MegaMan Battle Network 2, Sub Chip Memory increases the maximum number of Sub Chips one can carry.

Locations
Normal Difficulty:

Ticket Machine - Blue Mystery Data

Nupopo Statue - Blue Mystery Data

Hard Difficulty:

Park NBM - Blue Mystery Data

Super Hard Difficulty:

Sharo Area - Blue Mystery Data

Reg Upgrade Memory
Regular Upgrade (known as "Reg Up") increases the memory capacity for one's folder's regular chip. Each battle chip has a certain MB and if a folder has enough Regular Memory, this chip can be set to appear first in every battle.

Locations
Normal Difficulty:

Jomon Stereo - +1 - Blue Mystery Data

Jomon Monitor - +2 -  Blue Mystery Data 

ElecTower 1 - +2 -  Blue Mystery Data

Park Area 1 - +2 -  Blue Mystery Data

ToyRobo 1 - +1 - Blue Mystery Data

ToyRobo 3 - +2 - Blue Mystery Data

Dome Locker Room - +1 - Folded chairs

NetFrica - +1 - Center Pyramid

<span style="color:rgb(58,58,58);">Lion Statue - +2 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Antenna 1 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">NAXA Lobby - +3 - Space Suit

<span style="color:rgb(58,58,58);">Undernet 1 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Meteor 2 - +3 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Hard Difficulty:

<span style="color:rgb(58,58,58);">ACDC Area 1 - +2 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Town Area 1 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Jomon Monitor - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">ElecTower - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Park Area 1 - +2 - Blue Mystery Data

<span style="color:rgb(58,58,58);">ToyRobo 1 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">ToyRobo 4 - +2 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Netopia Area - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Undernet 2 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Ice Cream Stand - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Sharo Computer - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Super Hard Difficulty:

<span style="color:rgb(58,58,58);">ElecTower 2 - +2 - Purple Mystery Data

<span style="color:rgb(58,58,58);">ToyRobo 4 - +1 - Blue Mystery Data

<span style="color:rgb(58,58,58);">Yumland Area - +2 - Purple Mystery Data

<span style="color:rgb(58,58,58);">Meteor 1 - +1 - Blue Mystery Data

Expansion Memory
Expansion Memory is collected to increase the map space of the Navi Customizer. Only 2 exist in the game

Locations
The first one is found on the statue in front of Netopia Coliseum, while the other one is in Undernet Area 2.