MSN automatically sending message to contacts

[malaizai]

My msn did send message with a *censored* webpage link to my contacts without my knowledge.

There was no detection of any viruses with my AVG antivirus scan.

Is that my anti-virus doesn't has strong enough immunity to detect the infection?

[kpac]

Follow the advice here. http://www.computerhope.com/forum/index.php/topic,46313.0.html
If there are any steps you cannot do, make a note of it and continue with the next one. Post the results of the three scans here when finished.

Is that my anti-virus doesn't has strong enough immunity to detect the infection?

Not necessarily. No anti-virus program can detect all viruses.