Prevent Yahoo install?

Software Restriction Policy on W2003 server, clients are XP SP2.
I’ve set up specific paths to the files that are installed, but still yahoo runs.
Set up both, user and computer. then peeled back one or the other to see if I can get it to work.
I’ve read documentation and what I’m doing seems to be inline with that.
Anyone have any guidance?
never mind- she’s working now… just had to run a Hash instead of path.