Hey, thanks for the replies,
The only reason i came up with the conclusion that it installs the appropriate toolbar for the default browser is because...
I installed it accidently on firefox, and when i went back into firefox after the install it poped up telling me that yahoo toolbar had installed. then i uninstalled the toolbar using the add on manager on firefox
I assumed that installing the toolbar would naturally just install it for IE, and usually these toolbars show up in add and remove programs - anyway i checked and i couldn't find yahoo toolbar listed so i uninstalled ccleaner and the firefoc yahoo add on (which annoyingly set my default search engine as yahoo) and then i set IE as my default browser...
Reinstalled ccleaner with the yahoo toolbar option enabled and then there it was only on IE no installation on firefox and in the list for add and remove programs
Strange, but i guess clever also
Again thanks for the replies
Rob