Hello All,
My problem is bootscan will not run on my Windows Home Premium 64 bit computer…the program does restart Windows but no scan is initiated.
I have found old forum posts stating that ver 5 would fix this problem and I am now using ver 9…
I apologize if this question has already been answered, please help! Bootscan is probably my all-time favorite attribute of the Avast product line…
Any other security software? If uninstalled how was it removed?
Why are you wanting to run a boot scan?
A boot scan should be done “only” if avast detects an infection and suggests you run a boot scan.
I haven’t ran a boot scan in years.
Try a repair…Control Panel>Uninstall a Program>double click “avast”>click “repair”>reboot.
I have Windows Defender and recently (post bootscan prob) downloaded Malewarbytes. I have already tried the Avast repair option this morning. I like the bootscan option because of the sense of security given from scanning while the computer is in pre-boot state…
The running of a “boot time scan” is a matter of personal preference as running pre boot does in fact allow the scanning of files etc not accessible during regular running. 
I on the other hand run boot time scans once a month.
Disable Windows Defender. It’s useless anyway. 
This issue is still unresolved…
I haven’t run a regular scan in years. I do only Boot time scans.
Personal preference and since the boot scan occurs before the full OS starts, it does have access to files normally not available for scanning. 
The user needs to be aware that the boot scan can cause a non bootable system if incorrectly used.