To unlock all factions for M2TW is really simple.
There are two ways.
The first is:
1. Go to your "Medieval II Total War" folder.
2. Right click on the preferences.cfg file, select the properties tab and uncheck the read only box, then open it with notepad.
3. Scroll all the way down to the bottom of the file.
4. Add the following lines:
unlock_campaign = true
5. Save and exit the file.
The Second way is:
1. Go to the "Medieval II Total War/data/world/maps/campaign/imperial_campaign" folder.
2. Right click on the file "desc_strat.txt", select properties and uncheck the read-only box.
3. Open the desc_strat.txt file in notepad.
4. Move all the factions from the unlockable section into the playable section. Make sure no faction is mentioned twice.
The file should look like this:
Code:
playable England, France, HRE, Spain, Venice, Sicily, Milan, Scotland, Byzantium, Russia, moors, Turks, Egypt, Denmark, Portugal, Poland, Hungary, end unlockable end non-playable Papal_states Aztecs, Mongols, Timurids slave end
All the factions that were meant to be playable are now unlocked.