Download a program called BHODemon.. it prevents Browser helper objects (BHO's) from loading.
BTW: the extension is rarely (if ever) .BHO; it's generally just a .dll file.
I think HijackThis just lists the different BHOs, etc on the system, but does nothing to fix them.
Removing system services: On win9x/Me there are no services.
On NT/2k/XP, go to the administrative tools control panel > Services.
It might not be listed, in this case go to start>run and enter msconfig
You can disable services from there so you can remove them. Be sure to choose selective startup so it actually disables it!
However BHOs aren't really loaded as an NT service, it's a DLL that's loaded as part of IE / Explorer really.
Also, easy way to protect yourself in the future: Stop using IE. Use a browser like Firefox, Opera, etc. These browsers will make it difficult (or impossible) to install BHOs.
www.getfirefox.comwww.opera.com