E10) Can I avoid viruses by avoiding shareware/free software/games?

No.  There are many documented instances in which even commercial
"shrink wrap" software was inadvertently distributed containing
viruses.  Avoiding shareware, freeware, games, etc. only isolates you
from a vast collection of software (some of it very good, some of it
very bad, most of it somewhere in between...).

The important thing is not to avoid a certain type of software, but to
be cautious of ANY AND ALL newly acquired software.  Simply scanning
all new software media for known viruses would be rather effective at
preventing virus infections, especially when combined with some other
prevention/detection strategy such as integrity management of
programs.


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