I feel almost stupid writing this but it is just the stupid reality of using and relying upon IT to get us through the day.  The hundreds of times teachers and students come to me and tell me about a problem with their computer that is fixed by a restart is amazing.  In fact I am suggesting it is around 90 percent of the time.  We have a motto here that an IT problem is not a problem until you have rebooted the computer.  That's the best tech support advice I can give anyone alongside backing up your work regularly.  RESTART Guys