i looked on gamefaqs for cheats but they dont work...why!?!?

press tab and then write nwctrinity ( it gives 5 archangels in hero empty spaces )
This always works :) and its more than enough for you to "summon" help in very tough situations :P

Cheats for HoMM3 changes with every expansion. You'll need the HoMM3-Complete specific cheats.
Here's a list
Press tab. Enter Code. Press Enter.
If you use them, your score will be marked "Cheater!!!" instead of an actual score value.

By the way, much prefer cheat codes from Restoration of Erathia... Ni!

HOMM3 takes the cheat codes from the latest expansion, which in this case, is The Shadow of Death, with the theme from the movie "The Matrix", which is why nwctrinity works.
Press Tab, then type in whichever code you want for the desired effect.
Cheat Code / Effect
For example, hit TAB, type in "nwcneo" [without the quotes], then hit ENTER in order to get an instant win. You will be tagged as a Cheater, however.
nwctheconstruct / 100,000 Gold and 100 of Every Resource
nwcthereisnospoon / 999 Mana and All Spells
nwczion / All Buildings
nwclotsofguns / All War Machines
nwcphisherprice / Alternate Color Scheme
nwcagents / Fill Each Slot with 10 Black Knights
nwctrinity / Fill Your Army with Archangels
nwcfollowthewhiterabbit / Full Luck on Your Hero
nwcmorpheus / Full Morale on Hero
nwcneo / Gain +1 Level for Hero
nwcbluepill / Instant Loss
nwcredpill / Instant Win
nwcwhatisthematrix / Reveal Full Map
nwcignoranceisbliss / Hide Full Map
nwcoracle / Show Full Grail Map
nwcnebuchadnezzar / Unlimited Movement for Hero

WOuld it matter if I had all the expansions for it? Do I still need the specific cheats for each one or would any work?

Don't fret over getting cheats for HMM3. Because it can all be had through the map editor. You can set up your own maps, give your hero gold & other resources, any of the artifacts, any spells, set up any castle you want, etc. And your game score DOES NOT include "cheater."

I enjoy using the map editor as much as the game itself. And many people agree with me that HMM3 is the best of all the 5 HMM games. HMM4 & 5 had map editors in the planning stages, but they never came to fruition.

Are there cheat codes for HMM3/Master of Puppets?