I've had Morrowind installed before, and at the startup, all the mods that were activated were loading - like it would say: "Loading - Farmstead.esp"

But it doesn't do that. To make things worse, none of the mods even CHANGE my game. Texture and mesh replacers are working, but the ESPs aren't. My INI isn't read only, the files are activated in the launcher. I only have 6-7 mods activated.

Can someone help?

which mods. game has which language, is it the same as the mods? did you start a new game with a new character?

I'm currently using:

TextureFixV2.esm - Fixes terrain texture abnormalities
AccurateAttack.esp - Missing enemies with melee is almost non-existant
AIM_MW_1dot0.esp - Armor overhaul
EnchantingMadePossible.esp - Chance for successfully enchanting items yourself is much easier(depending on your enchant skill)
FatigueRegen.esp - You slowly regen Fatigue while running, and alters fatigue regen to closely match Oblivion
Oblivionized Enchanting Costs.esp - Cost for enchanting by an NPC is lowered to be close to Oblivion
Less Carryweight.esp - Lowers carryweight to 2.2 x Strength

Some work, such as: Less carryweight, Accurate Attack, and Fatigue regen. However, the others don't even work. I'm pretty sure the mods loading at the start of the game isn't a problem, but I can't figure out why some don't work. The ones that do work only edit game settings, so that could be a factor.

I only added mods during my playthrough of the game. The game is running in English, and all the mods are English as well. My game is also up to date.

Which OS are you using?
If it's Vista or Win7 you need to http://www.gamesas.com/index.php?/topic/781497-vistawindows-7-problems/page__view__findpost__p__11352753 for most mods to work.

Hmm...I am running Windows 7. Will I need to reinstall the game, or will a simple move of the game files be enough?

EDIT: Sorry, I read through the link you gave me too fast, and I missed the part about moving the files until I read it again. The different directory trick seems worth a shot, I'll try it.

Edit 2: It didn't work. What's worse is the 'Play Game" option in the launcher is broken, I had to use the regular Morrowind.exe

i use only the exe. i haven't seen my launcher for years. don't worry about that.

hm i don't know the mods you use, maybe they have startup scripts? do you checked the readmes concerning mid-game installation and savegame compatibility?

No, none have startup scripts. As far as I know, they should work fine, but the game persists as if they haven't been activated.