New Software found every boot

What you could try is to connect the GPSMAP to a PC and then check whether there's a file called gupdate.gcd in the Garmin folder on the internal memory. If this file exists, delete it.

Thanks that resolved my issue!! 

Deleting the .gcd will get rid of the prompt. However, the fact that it recurs even though you have actually INSTALLED the update is worrisome. It might be worth opening a support ticket to make sure the update worked fully.

Note that "validating" is the first step. After it validates, you should see "installing" with a progress bar. Then a reboot. If you never saw the "installing" message (not even the very first time), something is wrong.