Hi Janus,
Wow, a lot of questions and good ones too! I'm glad you have asked because I'm sure there are many parents and families in the same position.
This question first about Smiley Central has been asked before and is truly difficult to sort out for many people.
First of all, it isn't harmful. They do sponsor some free content (smileys for emails, etc.) that comes with a Funweb products searchbar and tool bar that is not malware, but is sometimes an unwanted application by some users. The Myweb searchbar had a history of being installed on PCs without a users consent and was considered an adware product because it bundles the toolbar and other programs into it's free offerings. Adware is not always a bad thing (or malware) unless you did not install it knowingly or can remove it easily once installed.
It is a low risk software should not harm your machine or compromise your privacy and security unless it has been installed without your knowledge and consent.
If you are running Vista your users should be on a Limited User Account, unless you chose to override the UAC (User Account Control) that is a built-in security feature of Vista.
User Account Control Overview
http://technet.microsoft.com/en-us/windows...a/aa906021.aspxProvided the children are running as Limited Users, your overall system security is much less at risk in the event of an unwanted application being downloaded or installed without your consent.
Vista also includes some very nice parental control features that are available as well:
Vista Parental Controls
http://www.microsoft.com/windows/products/...alcontrols.mspxYou might want to bookmark some of these recommended help sites for parents with children in the household using computers.
Teach Kids to be safe online visit:
http://www.bewebaware.ca/english/default.aspxMicrosoft Security At Home: Protect your family
Child safety
http://www.microsoft.com/canada/athome/sec...en/default.mspxA parent's guide to online safety: Ages and stages
http://www.microsoft.com/canada/athome/sec...rentsguide.mspxDo be careful using ecards as some malware has been known to spread using spoofed ecards or email. Only accept those that you know and are expecting. Unexpected ecards are not a nice suprise and could be a security risk if it happens to be the habit of a user to open these or click on links because of the known tendency of malware to ecards as a social engineering exploit.