Well, another trick could be to launch a file or small app from off that Machine. Depending on what you launched it should tell you that the volume couldn't be unmounted coz XXX is still in use. I tried it with a Photoshop image and the volume unmounted without a problem, however launching a PDF produced the error as you want. Cheers, Coj nk <netkat at comcast.net> Sent by: x4u-bounces at listserver.themacintoshguy.com 09/02/06 10:35 AM Please respond to "A place to discuss Mac OS X for the casual user." <x4u at listserver.themacintoshguy.com> To "A place to discuss Mac OS X for the casual user." <x4u at listserver.themacintoshguy.com> cc Subject [X4U] Prevent accidental unmounting? In a fit of I dunno what, I un-mounted another Mac which was connected to my main mac, and which was quite busy doing network 3D rendering. I was hoping I'd get one of those "Can not unmount the server because it's in use" things. no such luck. Aside from just hiding other computers in the sidebar, is there another way to protect myself from dumb mistakes like that? nk