Log on to that account and run a thorough check for hijackware.

Checking for/Help with Hijackware
http://aumha.org/a/parasite.htm
http://aumha.org/a/quickfix.htm
http://aumha.net/viewtopic.php?t=5878
http://mvps.org/winhelp2002/unwanted.htm
http://inetexplorer.mvps.org/data/prevention.htm
http://inetexplorer.mvps.org/archive/tshoot.html
http://www.mvps.org/sramesh2k/Malware_Defence.htm
http://defendingyourmachine.blogspot.com/

When all else fails, HijackThis v1.99.1
(http://aumha.net/downloads/hijackthis.zip) is the preferred tool to use.
It will help you to both identify and remove any hijackware/spyware. **Post
your log to http://forums.spywareinfo.com/,
http://castlecops.com/forum67.html or http://aumha.net/viewforum.php?f=30
for expert analysis, not here.**

--
~Robear Dyer (PA Bear)
MS MVP-Windows (IE/OE, Shell/User, Security), AH-VSOP


T1J wrote:
What's the difference between running the internet explorer 6.0 sp2 on
Limited Account and Administrator Account? because sometime when use IE
6.0 sp2 on administrator to browse the internet i see information bar
pop-up that has a blue shield/question mark i think it's a security
questions icon with message this site might require the following ActiveX
control: click here to install on a the website but when i use IE 6.0
sp2 on limited Account i don't see the information bar at all that has a
blue shield/question mark icon. can some one explain please? or direct me
to a website which explain the difference when running IE 6.0 sp2 on
limited and administrator.