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

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.

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

Locations
''There are only two Extenders you can find in this game. The first one is found in the in front of Netopia Coliseum, while the other one is in Undernet Area 2 BMD.''