I just installed Windows 10 on my 64 bit system and seem to have a hang--.the screen is flickering on and off with the background up, Cortana and task bar up but no icons. The spinning circle is on and I cannot click the task bar successfully. Has been going on for 8 hours now after an apparent successful upgrade. This started after I entered the logon password.

It seems to be doing something as the frequency of screen blink changes. Taskmgr shows nothing hung but the intel storage processes are 20%. It is a scsi system so I wonder if the drives are rebuilding? Suggestions?