Consider that some bacteria can exist in two forms, and active and dormant, where the dormant form is effectively "dead," or as other posters have noted, "non-living." Under the correct conditions, it becomes active and alive -- much lthe same like the virus.
There is a difference between non-living and dead. In order to be dead, you have to have once been alive. Perhaps a better way to look at this would be that a virus is itslef not a living being, but it needs a living being to survive.
One life function that all living things carry out is reproduction. Since viruses must invade a host cell and take over the host's reproductive machinery in the cell to make more viruses, it is not technically a living thing. However, it does have its own genetic code of RNA or DNA, surrounded by a protein coat.
The answer depends on what state the virus is in. If the virus is simply its own cell, not attached to another non-viral cell, it is dormant and not "alive." Once the viral cell attaches to another non-viral cell, then it becomes "active" and can be considered a living cell.
Therefore, on its own (simply DNA or RNA surrounded by a protein shell), it is not technically "alive." It is only when it joins with a host cell that it is able to live and reproduce.
Viruses are classified as non-living by most scientists. They do not breathe, eat, or do anything at all, really. When a virus attaches to a living cell, the attachment is a mechanical one, like a key fitting into a lock; the virus does not have to "do" anything to attach. Although a virus can take over the functioning of a living cell, that alone does not mean that it is alive. Many chemical toxins change the way a cell acts, too, and they are not alive. While the interaction between a virus and a host cell is complex, only the host cell is living. The virus is more like a robot.
Viruses are not living things. Viruses are complicated assemblies of molecules, including proteins, nucleic acids, lipids, and carbohydrates, but on their own they can do nothing until they enter a living cell. Without cells, viruses would not be able to multiply. Therefore, viruses are not living things.
When a virus encounters a cell, a series of chemical reactions occur that lead to the production of new viruses. These steps are completely passive, that is, they are predefined by the nature of the molecules that comprise the virus particle. Viruses don’t actually ‘do’ anything. Often scientists and non-scientists alike ascribe actions to viruses such as employing, displaying, destroying, evading, exploiting, and so on. These terms are incorrect because viruses are passive, completely at the mercy of their environment.