shola,
I would suggest that we start with a simple repair of Avast.
Normally, Avast does not affect the loading of MS Outlook unless there is a file corruption.
Has Avast ever worked properly with MS Outlook?
Go into Start/Settings/Control Panel/Add-Remove.
Click on Avast to highlight it, then Remove.
You should be given an Option to "repair" Avast.
Click on the Repair option and let Avast repair it's files.
Try to load MS OE again and let me know any error message that appears.
Later.