Edit: But nehrim is a OB mod so it would require OB wouldn't it?
When I said: "and then when I want to play oblivion again just do the opposite?" I meant play oblivion without the total conversion Nehrim. I sorta think of Nehrim as another game just because it is soo different.
I believe Nehrim has its own Exe, so it can be played like it's completely separate from Oblivion.
But doesn't it still install it to the same place as other mods?