It is possible the trojan is trying to inject itself onto the system by using Rundll32 and cannot start. This could be good news, but temporary. You will need to clear your system of all potential rogue software. The registry is almost certainly corrupted in this instance and you will never have 100% certainty you are safe, according to Microsoft guidelines, without a completely clean install.
However, by using several freeware online tools, there is a possibility you can resolve the issue, at least for the most part, or on a temporary basis.