![Install Install](/uploads/1/2/5/4/125423885/301312993.jpg)
Click to expand.A standard erase of a 160GB 7200 rpm HD should only take much less than 1 hr. Can't think what's gone wrong other than the HD has suddenly developed a mechanical problem.
There is no progress bar for an erase, just an activity strip at the bottom right showing names of what is being erased & reformatted. That moves too quick to read most of it as I recall. Please report back on the final outcome to add to the knowledge base. In Steve's case, if there is no activity strip, I can only guess that you did not boot from the optical drive in order to perform the Disk Utility HD maintenance. An error message under that circumstance might be helpful, but I guess there isn't one.
![Installer Installer](http://cdn.osxdaily.com/wp-content/uploads/2014/10/choose-install-os-x-yosemite.jpg)
The only difference in this instance, after formatting and partitioning the flash drive, we'll be installing OS X Yosemite on to it, where before, the OS X installer was copied onto a USB 2.0 boot.