HEy, I need informations on how to install Obge. Does anyone of you have any clue?

When I open it there is a "base" folder and a "core" folder. Which one of those do I gotta use?

Download the latest version, OBGE Core v3.1.0.0 RC4, from http://code.google.com/p/oblivion-graphics-extender/downloads/detail?name=OBGE_v31rc4.exe&can=2&q= or just http://oblivion-graphics-extender.googlecode.com/files/OBGE_v31rc4.exe and choose "Save Link As". Since you already had problems with the manual install i suggest you go with the .EXE file.

Double click it, if necessary navigate to your Oblivion instalation folder (but it will detect it automatically), click "Next" and choose "The standard extender - supporting shaders and effects". Other options are for OBGE controller so you can change settings while ingame. I wouldnt use it because you can tweak everything via ini file, plus it takes up one esp slot so...
Click "Next".
If you're not sure you have the latest DirectX installed (which is required btw if you want OBGE to run correctly) choose this option also while still in setup. It will automatically unpack everything in correct folders. And thats it, OBGE Core is installed.

If for some reason you still want to install it manualy then you need to:
- Download and open http://oblivion-graphics-extender.googlecode.com/files/OBGE_v31rc4-BAIN.7z
- Inside the archive open "00 Base" folder and drag "shaders" and "textures" folder in DATA folder (...Oblivion\Data)
- Go back one step (inside the archive ofc....press backspace) and open "Core" folder. Now drag "OBSE" folder in DATA folder (...Oblivion\Data)

Thats it.