how do i isolate the computer virus in new vegas, i know its random but there has to be a clue to solving it.

You randomly solve it, though i think its a waste of time just because how annoying it is to do..

If the BOS computer has a virus, the interface appear differently and the option to isolate the virus will become available. If you don't have high enough science, you will have to be quick and get all three within a certain time frame or you will need to do it again.

Get enough science. Or click wildly on computer terminals until you get lucky and find all three of them. I have no idea if turbo would slow down time or not.

Trial and error basically. Just keep opening terminals and, with luck, get three virus.

The "normal" terminals have a bunch of intellectual garble whilst the terminals with a virus say something cocky like "Still not found the other two?".