Help none of my changes in the construction set show up in game

recently i have tried to add a custom weapon into oblivion i got the weapon in fine and it looks good in the construction set but when i place it in the game and then save the esp and put the x on it in the oblivion launcher it not there when i go to pick it up. at first i thought it was my mesh but i put a regular steel sword in sane thing happened i tried moving stuff it all looked right in the construction set but in-game nothing changed i made sure to save to an active file , also when it saves the esp i go to the data folder but i cannot find it but the oblivion launcher and the construction set both say the esp is there. i have also tried reinstalling oblivion and the construction set. Also im using windows vista premium.

any help is greatly appreciated.