Well, I installed a few mods and now i've got the purple textures issue.
I could fix it if had had the original textures, but I cant find them anywhere, does anyone know where I can find a download of them?

Oblivion - Textures.bsa.

There are a bunch of bsa managers, OBMM comes with one.

What I mean is that I need the default vanilla textures, maybe you know where I can download those?

Are you using OBMM to install mods? if you are it has a form of Archive Invalidation called Bsa Redirection, and the ability to reset the Bsa timestamps. The original textures should still be in the Oblivion Bsa's. The Archive Invalidation is in the Utilities section of OBMM.EDIT The Bsa's are in the Oblivion\Data folder.

The specific bit of information that nobody is stating is that mods do not overwrite the vanilla textures, so they can't be lost. If anything ever tells you to replace the original bsa files, don't install it, because it's not a proper mod. The mods that provide bsa files do so as additions, not replacements.

To restore a texture, you need only delete the overriding one. "Missing" textures are not the original ones disappearing, but a new mesh (or overriding one) wanting a non-existent texture, and that can be solved by removing the overriding mesh, or correcting it.

Didn't Work, all I have in my data texture files are three folders named menus, menus50 and menus80, inside each one of them a world and map folders and inside those a dds file named cyrodiil_resized.
I looked for the vanilla textures but I didn't find them anywhere, maybe you guys know?

You do still have the file "Oblivion - textures.bsa" in your "Data" folder, don't you?

They are not in the "textures" folder, or rather they are in a textures folder inside the bsa compressed archive that Windows Explorer can't expand. Because the folder is inside the archive, it's pretty well immune from being overwritten.

OK, got the compressed file, can you please repeat what I need to do step by step?

No - what everyone is telling you is that all of the original game textures come compressed in the Oblivion\Data\Oblivion - Textures.bsa file -- that file has all of the vanilla textures and mods do not change that file in any way a mod just adds it's textures into your Oblivion\Data\Textures folder and the game will use that file if it exists and once you remove it or it does not exist then the game reverts to using the original texture from inside the compressed Oblivion - Textures.bsa file ---- so there is no way to "LOSE" the original texture (unless you use a BSA packing utility to remake the Oblivion - Textures.bsa file without it.) So to get back an original texture all you have to do is delete the replacement texture that is in your Oblivion\DATA\Textures\ folder and the game will then revert to using the one stored in the BSA.

OK, first thing is to discover what item has a texture problem. Open the console and click on it. That should display its formid at the top of the screen. The first two characters are the hex id of the mod that did it. If they're 'FF' then it was spawned during play and will be harder to track down without FormIDFinder or Refscope or some similar plug-in. If they're '00' then we don't believe it! Except....

Armor or other clothing would be a problem with this method, as the console will show you the wearer's ID, not the equipped item's. Then you would need one of the other tools.

Usually it's a replacement mesh that installed without its new texture, and uninstalling or re-installing the mod will correct it.

The mod numbers are serially assigned by your mod load order, so '00' is Oblivion.esm and so on. You'll have to look up your load order to translate the number to an esp or esm.

I think the wording of your post might be adding confusion, If the purple objects are items that you added by using a mod, then you need to install the textures for those items. The textures should be part of a download, most mods come with thier own meshes, textures, and an esp file, You will need all three installed for a mod to work. You need to install them into your Data folder with a utility like 7-zip.

Deleted the texture folder in the data and still nothing changed. the only texture that changed is the landscape, it's a purple version of the game map, sorry if I haven't mentioned it yet, maybe that helps

AHHH --- thats a different problem !! --- that is caused by the shaders not being updated properly when patching the game to the new 1.2.0416 version !!! to correct it http://www.tesnexus.com/downloads/file.php?id=20348and replace your existing shader folder contents with them and it will fix you up !

Thanks! solved my problem, sorry about all the fuss I made, you're great guys!

I will recommend using Oblivion Mod Manager for installing and removing mods. OBMM removes all the files of a mod that has been converted into an OMOD,
You could convert your map mod into an OMOD, install it and then uninstall it to remove it completely from your Data folder. The readme for OBMM is accessed by using the help Button.
Use the pinned topics of the Oblivion Mods section of this Forum and the first link in my signature for information on installing and using mods.
The reason you you have purple textures is the mod that you want to install needs textures from another mod. The Installation instructions should be in a readme file in the mod you installed, and should name the mod that has the proper textures.
EDIT I need to type faster, glad it was just missing Shaders.

No Problem - just glad we could get it sorted ! ENJOY !