Music software reinstall - older version still exists?

Hi
I plugged in a mates ipod into desktop (dell) just to recharge (op system win xp) & for some reason managed to lose access to itunes.
I tried to reinstall i tunes but comes up with error message:

"The older version of Apple software update cannot be removed. Contact your technical support group"

I contacted apple support & they went through basic remove programs & into msconfig & do system restore & at least the software now says its removed when i go to add/remove programs.....but try & dowload itunes again & get same error message.
Apple supprt said i have to go to dell as its an issue with the operating system. However, i cannot see how or why.
Would appreciate any ideas.
Can i go into regedit & remove any other hidden files etc?
Obviously i cannot access any of my music library without installing a different music application....though i have my own ipod so i wld like to stay with itunes.
Many thanks.
R

 

many thanks halo, worked fine.