Chance has it that there is still some malware remaining on the system. You can try booting into safe mode with networking if it is a Windows based OS. This will enable you to connect to the Internet and download some additional tools for detecting and removing malware. Examples include Spybot Search & Destroy and Somarsoft Ad-Aware Personal Edition. I would try to install, update and run those to detect and remove any remaining malware.
In the meantime, something else that you can try is running MSCONFIG from a command line or the Run dialog and disable all non-Windows startup items; however, this is only a temporary solution which should prevent most, if not all programs from running upon startup and may allow you to troubleshoot and run the above programs.
I believe that your computer system has been badly infected with this type of virus software program. The most important thing you can do is to scan your computer system using your latest and update antivirus software. If there is no remedy at all, you should reformat your computer to wipe out the entire content of hard disk.
Once a certain virus software already penetrated and modified some files on the system, it is really hard to recover the entire system again. The best thing you have to do is backup your important files and perform a full system scan as much as possible.