I ran the Housecall test on my computer (housecall.trendmicro.com) and it cleaned one virus and found three other items that it said could not be cleaned.
It identified them as:
So now what do I do?
Try downloading the free version of the AVG virus scanner from www.grisoft.com . I have had very good luck with it, it can clean trojans that others leave behind.
If you want to try your hand at cleaning them yourself, there are instructions at Symantec:
I’m not finding anything about TROJ BLKSTONE.A
Techinal info on TROJ_BLKSTONE.A:
Warning: if you attempt the removal by editing the registry, make copies first, if you have little experience, it is better to use the latest antivirus from Norton, Symantec, PC-cillin or others.