Its sometimes not a bad idea to run an alternative antivrus scan.
panda active scan
I use E trust on my machine then once every 3 months or so scan with panda online.
You will need to use internet explorer as your browser. The Panda website will place an active x on your computer, all safe and above board. It just takes time. oh and turn off your trend and or any other AV yuck wear live scanning programs before scanning with panda. They may clash.
Sometimes Panda will pick up on things the other Av doesnt.
Clean out your temporary internet files. I do this manually with win XP. Right click your start button, left click explore, select and open your user name. select local settings, select temporary internet files, select content.ie5 empty the contents of each file to your recycle bin. select files using the shift and arrow keys then hit delete if you encounter a message
that "this is a system file" choose do not delete. There is probably a program to do this automaticaly someplace (?CCleaner?) but i find its just as easy to use the manual method.