Most of the time, when you have originally detected the malware issue, it means the computer is infected by malware of some sort. Antivirus scanners may not show a sign of the malware still being there, which could be a sign of a rootkit.
Whenever rootkit scanners, and antivirus software scan for the rootkit, it gets as close to the system kernel as possible. If the rootkit is beyond that point, it will not be detected.
So, the idea is, is when you post to a forum that you need help removing malware, it is best to stay with the helper, to ensure your computer is clean. However, it is up to you to continue or not.