[garganzol]

An average user is a myth. Every kind of average user has its own traits and they differ widely.

That's why there is such thing as system settings.

And yes, most desktop users are conscious when they work with files. Windows by default suggests "My Documents" folder as a target destination which is a pretty sane safe choice for all traits of average Joes.

[UK-AL]

That not the issue though. Programs that plaster your registry full of crap or replace or change os files etc

[flukus]

That can be solved by not requiring admin privileges to install software and getting rid of the registry, which was an awful idea to begin with.

[swiley]

Don't run stuff as root then.