Down loaded new nortonantivirus from tiscali seams to be slowing down lap top any sugestions

Unfortunately many antiviruses tend to slow down things: they have to check each file on execution.

Check that your antivirus isn't scanning your whole system just now. Many antiviruses will do that upon first installation, to be sure they're running on a clean system. If that's the case, wait for it to complete.

If this happens often, there's a "speed" setting - fast scan will make the computer slow, but slow scan or "idle scan" will load the system much less. Try those.

Otherwise, maybe another antivirus might work better. I've always found ESET's NOD32 very light-treading even on not-exactly-bleeding-edge computers. Another one is AVG, of which there's even a Personal Free edition.