The latest verson of A-aware does not even find the ISTsvc.exe on my computer. F-prot detects it as a backdoor or security risk but says it cannot delete it. I have got other such files (like msbb.exe, etc.) which I know are spyware but am denied access to delete them. I followed the above advice about ist but it is still there. The last week now the toolbar at the bottom is always frozen. I don't know what to do can you help me fight it off? Thank you.

I found a way, finally. It involves going into your registry. I got the information from http://sarc.com/avcenter/venc/data/adware.istbar.html Or go to symantec web site and search for adware.lstbar. Unless you delete the lines in the registry placed there by this Trojan Horse, you won't get it completely off.