Making the user a member of "Users" group to prevent virus/spyware/adware infection

[John Doe]

I recently setup computer with Windows XP Pro for my parents. All they
need to do is to browse Internet and send/receive email. They don't
need to install any additional applications/games/etc, and if they
ever do - they will ask me.

They are not really computer literate, but have a general
understanding of what NOT to do. Nevertheless, accidental possibility
of their computer being infected with viruses and/or spyware is
something I've been thinking about.

So far what I did I made sure they belong ONLY to the "Users" group.

I think this pretty much resolves 99%(100% ?) of all possible
problems.

Am I right here ? Please feel free to correct me.

The reason behind this opinion is that all spyware/adware/etc. needs
to install itself, and since this user has no write access to anything
but "My Documents" folder, any installation will not be possible. Am I
correct in this assumption ? I actually never tried going to one of
these sites that install spyware IE plugins on your PC to answer "Yes"
when they ask me to install their app just to see what will happen :-D

 

[John Doe]

Clarification:

"I think this pretty much resolves 99%(100% ?) of all possible problems
(EVEN WITHOUT THE USE OF ANTIVIRUS/ANTI-SPYWARE software)."

 

[Colin Nash [MVP]]

Clarification:

"I think this pretty much resolves 99%(100% ?) of all possible problems
(EVEN WITHOUT THE USE OF ANTIVIRUS/ANTI-SPYWARE software)."

It certainly helps a lot (maybe 85%??? if you really want me to guess at
numbers.) It is possible for some applications (and this would include
spyware) to install themselves only under a specific user's profile. As
long as it doesn't try to write to restricted areas of the registry (i.e.
HKEY_LOCAL_MACHINE) or the file system (i.e. C:\WINDOWS or C:\PROGRAM
FILES), it is still possible something to be installed under a specific
user's profile. In a case like this, it wouldn't affect other users though.

It will always be important to be careful what you click on...