spware / malware / ...: sitebar and other files

I found this formum while trying to get rid of some crap on my computer. I'm not totally sure what I have but there is something here that won't go away. I have gone through the 'do me first' thing (http://forums.majorgeeks.com/showthread.php?t=35407) and found a bunch of things. I cleaned them all out but (almost) all of them have returned so I'm guessing I have a bigger problem that I need to find first.

I had been looking at this thread (http://forums.majorgeeks.com/showthread.php?p=663469#post663469) as it seemed like it might be close to what I have but no go.

Windows 2000, all updates have been done.

Here is a screen shot of what pops up when a network connect is made. You have also see some files on my c:\ drive.
http://www.redclaw.ca/images/help.jpg
After I close the sitebar window (using the 'x' in the top right corner) if I don't close the command prompt fast enough it opens IE and tries to get me to install other things.
I have deleted the following files a number of times but they keep coming back:
is.exe
low.exe
mmxateam.exe
tb.exe
ex.exe
zxvcc73x.exe

Ad-aware also finds the following entries which I clean but they alway return:

Vendor Type Object

DyFuCA Regkey Malware HKEY_USERS:.DEFAULT\software\ist
DyFuCA RegValue Malware HKEY_USERS:.DEFAULT\software\ist\exe_start

Here is a hijackthis log:
http://www.redclaw.ca/images/hijackthis.log

I have run all of the online scans and I have done / cleaned everything they found. I don't know what else to do.

If anyone has any ideas please let me know, also please post if there is any other information that may be of use.