When I put in a USB drive, VMWare asked me if I want to connect it to Mac or Windows, and the USB drive shows up in Disk Utility, so I can confirm that the USB is not broken and USB port is also working. But I can never find the USB drive in Finder. In Preferences, I checked everything so external drive can be shown in Finder. What's wrong with this?
(I use MacBook pro 15" Late 2011, OS X Mavericks)
You could try finding the drive using Terminal. If you're not hip to Terminal commands, the way to access your USB via the command-line is
Open up Terminal, and enter the following commands (hit return at the end to execute):
cd /
This will take you to the highest level folder on your computer's hard drive. Then, type:
ls
This will list everything there. You should see an entry there called Volumes. Now go into the directory and list its contents:
cd Volumes
ls
The USB's name should be listed, since you said DiskUtility sees it.
From there, you can browse the stuff in your USB, and use open [filename] to open things.
Otherwise, you might want to copy everything off of the drive and reformat it. That fixes most problems.
If the drive works fine in other Macs, try other USB ports on your Mac. Certain models of MacBook Pros have some odd USB port behaviors.
If the drive works fine on other OSes (Windows, Linux, etc) but not on your Mac or any others, then the drive may not be formatted properly.
If the drive works fine on your Mac if VMWare is not running, then there is a configuration problem (I don't run VMWare personally).
If the drive previously worked on this Mac, but no longer does, and no longer works on other computer either, then it has either failed or its filesystem is corrupt.
If none of that helps, please post a screenshot from Disk Utility while the drive is plugged in.
diskutil listshow? What doesls /Volumesshow? – grg♦ Dec 29 '13 at 19:50