An irritating condition continues to crop up with my Office 365 EXCEL app: without warning EXCEL will "hang" on simple, non-macro spreadsheets and even though Windows Task Manager Applications is showing the app as "running" I need to do a hard alt-ctrl-del force stop to kill the app-hang.  I then restart EXCEL but notice that there is a second instance of excel.exe *32 running under Windows Task Manager Processes which forces me to select "End Process" to kill the superfluous instance of excel.exe *32.

I Am running most current Office 365 subscription on a hp-450 Pro laptop with win-7-PRO.  All apps/windows/subscriptions are up-to-date.

Any guidance to correcting this is appreciated.