Are there any benefial viruses ? what are they, and what do they do..?

All viruses are harmful, in the sense of their way to replicate. Only those scientists who utilized their deadly 'function' in destroying some other pathogens or tumours in our body but this is just for laboratory trials(doing to mouse...etc), clinical trials result do not show promising treatment as virus might infect other cells than pathogens and tumours. They can remain dormant for years. When u discovered it, there will be the end..

Viruses almost always damage the host cells. Because viruses cannot reproduce on their own, they rely on the replication mechanism of the host cell to make more copies of themselves (i.e., they are obligate pathogens). Then, the new viral particles will exit the cell and search for another cell to infect. This exit is often very physically damaging to the host cell. Thus, viral infections can be detrimental because of the loss of function of host cells.

Are there any benefial viruses ? what are they, and what do they do..?mcaffee

mold...they make penicillin out of it

Are there any benefial viruses ? what are they, and what do they do..?norton antivirus 2007

You mean beneficial to humans... no for as much as i know they dont exist, theyre dormant at best, quite malignant at worst. Beneficial bacteris such as E. Coli are abundant and life on a marco scale couldnt exist w/o them. But virusues work on a genetic level to alter or arrest the DNA and RNA functions of host cells, quite insidious they are. So as far as I know, beneficial viruses do not exist.
according to me some are there beneficial in fact they are harmfully to bacteria so beneficial to us