External hard drive does not open or dismount. Stuck in "checking prerequisites" in disk utility
Hello
My Seagate external hard drive will not open or dismount. There are video files and IPhoto Libraries on this drive.
Using disk utility to check it, but has been stuck in "checking prerequisites" for 45 minutes. See snap shot.
Don't know what to do. Please help. Thank you.
OSX 10.9.5 Mavericks
MacBook Pro Retina