Resolved Upgrade from mavericks to yosemite seems to hang during reboot

[grandM]

Everything seemed to be alright till the reboot. The first status bar got filled
Slowly. Then the reboot. After an hour I am still at fifty percent. Black screen and white apple with status bar. Have a mini i7, no SDD. 16gb ram. I seem to hear some spinning now. is there Any Way To know What the operating System is doing. I have an external keyboard Connected to the mini through USB. Please advise.

 

[grandM]

It got solved. As it had passed the first progress bar the problem occurred during the reboot. So the progress bar concerning the reboot got stuck halfway. The progress bar concerning the installation had finished. After waiting more than an hour I rebooted. The reboot went fast and without any problems. I didn't even go into a secure reboot. Hope this might help other people running into the same problem.