Boot runner prevents Mac access!

At Mac startup boot runner screen is displayed with Mac,windows , and restore icons. Selecting anyone of the three just returns to boot runner so I cannot get acces to the Mac desktop and programs

Not sure what you are seeing, but you can disabled boot runner like this:

Reboot the Mac and boot into safe mode by holding down the shift key at the startup chime.

Boot Runner will not be shown when the Mac is in safe mode. Sign into the Mac, and delete Boot from /Library/PrivilegedHelperTools/.

Reboot the Mac and verify that Boot Runner no longer starts up.