cannot connect Samsung Galaxy Ace???

in vista i used to connect my phone (samsung galaxy ace) for music, files, etc. now i tried to do so but it wont work. on the taskbar it says 'safely remove hardware and eject media' but when i go onto my computer its not there. i don't know how to fix this because it used to work perfectly before on vista but not any more.

any help is much appreciated

thanks !!