who is checking your HijackThis logs? If used properly you can completely clean up your system with it without any risk to the system itself. for prevention I use all of the following now, and I haven't had a single problem in weeks.
Norton 2004 Extended threat (registered)
Trojan Guarder (registered)
Zone Alarm (free)
Socks Ad Blocker (free)
For scanning and assesment:
Spybot S/D (free)
Ad-Aware 6.0 (free)
I uploaded a lot of the good free ones and the unregistered version of Trojan Guarder to this site if you want to download it: http://www.mmi-hosting.com/~Cunjo/Ot...tuff/Security/
Please see BOTH of the readmes the one on that page, and the one that is in the SFX RAR archive.
Zone Alarm and Keiro come highly reccomended, and SpywareBlaster can help too.
EDIT: for good advice on those things, and to have your HijackThis logs checked for problems, try http://www.spywareinfo.com/forums
. they can help a LOT with those things.