Trying to start over but all my files are back

I have a non-steam morrowind and a steam oblivion. I tried intalling morrobivion before and I ran into some trouble. I was able to figure out was causeing my game to crash. I had some purple objects, which I understand to be texture issues. The main problem though was the game crashing immedialey as I entered morrowind, both sedya neden and ebonheart. I wanted to again to install everything but when I deleted and redownloaded oblivion though steam all my mods still seem to be in present. Does anyone have any advice or know of a way I can clear everything and just keep the oblivion files ot know a soultion to my problem?

this is not spam