DavidR
11
Probably best to do an uninstall, reboot, install, boot. and try again.
There is also an Avast Uninstall Utility, find it here that you could also run after uninstall to ensure every thing is removed.
You needn’t download the whole program again, why not copy the downloded avast-setupeng.exe and avast uninstall utility from your HDD on to a CD and copy that to their PC.