BNU update issues on XP SP1

There are 2 computer in the network, both running on XP
SP1.
Updated new update on one computer. Not able to update
BNU on other computer. Tried to remove software from
add/remove but asks for CD. And when insert CD, it says
newer version is present so wont allow to remove. Tried
removing software in selective startup and also in safe
mode with networking but gives windows installer error in
this mode.
I like keeping my things updated and would like to have
updated BNU software as XP SP2 is round the corner(though
I know it is not mandatory to have this software).
Please tell me how do I fix this.

Thanks in advance for any help.