i had not fully uninstalled nortons when i downloaded avast.
I guess you mean "when I installed Avast". Just downloading the Avast installation package will never do any harm.
So i uninstalled avast. next thing i know everything has gone haywire
You never should have installed Avast while NAV wasn't completely removed. This can give all kinds of problems.
could u tell me the name of that program
How can we tell you? It was on your system that this happend. None of us saw it.
is it safe to download avast again
Sure it is, but make sure that every trace of other av(s) is removed before installing.
my sis-in-law gave me her old computer and it has files on it the need ashsimple to open
ashSimple is the simple user interface of Avast.
No files need ashSimple to be present besides Avast itself if you want to open Avast in the simple user interface.