Not necessarily. Vista apparantly spawns a seperate taskeng.exe process for each scheduled task that's running.
Under the View tab in task manager, click to show hidden tasks. Then, click to show all running tasks on the right.
(I have no idea where the view tab is on the vista task manager, as i'm not on vista at the moment. The information on how to view them was taken from
http://forums.techgu...-processes.html).
It can't hurt to run a virus scan to be sure, but from what i've found, I wouldn't start worrying until there is a lot more than two of them.