Along with these potential orhaned entires, which I believe a-squared terms
'traces', are the 'risk' items already mentioned.
My own online scan included at least one such item called VNC, which as a
remote control application is considered potentially risky exactly like mIRC.
In my case I'm aware that this exists, though the detection and its two
associated traces might be considered a false positive by some who regularly
use it for its intended purpose.
Nothing within the 7 files, 2 traces and 1 cookie the online scan detected
were a true false positive, though when set to scan the entire disk the scan
is very agressive, even detecting items contained in the Avast! 'moved'
folder. However, it generally described quite clearly what the potential risk
might be, with only the separately detected VNC registry traces not clearly
associated directly with the related VNC file detection.
As with other antimalware which are scanning an entire disk there is always
a potential for items detected out of context to be false positives, so they
should be examined carefully. I've seen this with every scanner which allows
such a 'full disk' scan, so it's nothing new and simply reflects the level of
agressiveness designed into the scan.
I prefer to call such agressive detection 'noisy', which can be good or bad
depending on the audience. Someone wanting to find any trace of possible
malware would find this helpful while those only wishing to be aware of truly
active and operational items would find it annoyingly 'noisy'.
In those terms I find a-squared to be one of the more informative noisy
antimalware I've tried. I have no need for an additional installed
application however, since the management of each simply adds to the
potential for confusion including both actual false positive and/or real-time
detections, along with maintenance of updates and program upgrades.
Bitman