iTunes installs all sorts of crap.
I found uninstalling it left QT on the system as well as some sort of interface that Device Manager told me couldn't have it's drivers updated even after re-installing iTunes.
Uninstall everything from Apple you can find, then browse through your hard drive for their crap and delete it.
Places to look:
After this, run a decent registry cleaner and fix the references to all those files and folders you just deleted.
C:\Program Files\Common Files
C:\Documents and Settings\All Users\Application Data
C:\Documents and Settings\%username%\Application Data
C:\Documents and Settings\%username%\Local Settings\Application Data
Next open regedit and search/delete anythin itunes realted (search for itumes) but BE VERY CAREFUL... it's better to leave something you're not sure of than remove something critical.
Then go back to your registry cleaner and scan for more errors - you'll probably find a load of activex keys that are now broken and can be fixed.
Then either re-install itunes or, even better, install the WinAmp plugin.