Hi, I am going to buy a clickfree external hard drive to back up my new, virus-free laptop. I also have an older laptop that may have a virus. I am wondering if I use the external hard drive to back up both computers, can a virus make it's way into my new laptop? (I don't know if this makes a difference, but I noticed when you plug in the clickfree, it recognizes different computers and I assume it keeps the backed up info from each separate). thanks