Chosen Solution

Normally no problem; recently boots but error notice: “cannot unmount disk; close all applications & files”. I re-installed last update to 10.6.3. Trying to find anything that could be open, deleted some apps, etc. So far, nothing works. Is there a simple way to find any open apps or files I haven’t found? I do have Time Machine set on the ext. HD but haven’t yet restored from last month to see what changed. Tried booting from 10.6 install dvd. Same answer from Disk Utility.

Finally found a solution. After so many trials & errors, I may have lost track of each. Downloading & re-intalling the 10.6.3 update, cloning my HD to the external boot device anew allowed me to run Disk Utility & other maintenance. These appear to have been the solution.

Try a “Force Quit” to see what’s open. Command + Option + Escape

I know this question has already been answered, but… Typing “lsof” (stands for: list of open files) in a terminal prompt will give you a list of all open files and the name of the process that has them open. Use the kill command with the process number to kill whatever process has the files open you want closed. Afterwards you should be able to unmount the disk.

Thank you, mayer. I hadn’t thought of that. Sadly it tells me only Finder is open. At some point I will try reinstalling Snow Leopard.