not able to install IE 5.5 on Win2k Term

on win2k Server i have Terminal Services installed & running. i want to install IE 5.5 on this server. since Terminal Services is running on server i tried installing IE 5.5 from Add remove programs (install Mode). at the end of installation the program says another application is running please close all the application & try again. but none of the Terminal server users are logged in to server & i dont see any programs running. i tried to install it from safe mode but no luck it throws same error again & exits from setup. whatz causing this ??