I am new to Avast. Every time I run a scan it deletes my passwords how can I stop this
First I would suggest stop running the scans and what scan is it you are running ?
What passwords are being deleted ?
With a resident (on-access) antivirus scanner the need for on-demand scans is much depreciated. For the most part dormant/inert files are being scanned, the other active files are going to be scanned by the resident shields when they are activated.