Hi Calico :
To avoid any possible "conflicts" with Avast, it usually
MORE than just "uninstalling" the prior antivirus,
particularly if its either Norton or McAfee. Should use your
computer's "Search > All files and folders", using the
search "term" "McAfee" and "delete" all appropiate items.
And to be extra cautious, it would be advisable to run a
registry cleaner to find any items there.
There has been "talk" on this forum that McAfee is not
that easy to completely remove from a computer !?
There is even a "thread" on the "PC De-Crapifier" to get
rid of programs like McAfee .
If you have not already done so, you should RIGHT-click
on the Avast icon in the System Tray, clicking "VRDB" to
"generate" it AND clicking "Program Settings" and go
through them, setting them to your preference.