Last night i installed the latest automatic update from microsoft (Malicious Software Removal of September 2011). it appears to have removes some iTunes components so that they no longer work (Apple Application Support). also the iTuners uninstaller got "stuck" so have cancelled. i am reinstalling iTunes. caution!
NOTE: I have re-installed all 3 components. this makes me want to switch to an iMAC !
(this "Malicious Software Removal" Tool has also uninstalled my CanoScan 9000f scanner driver. who knows what else!)