Full Scan into 7th hour on Latitude 100L

I just reinstalled XP for my sister-in-law on her Latitude 100L (2.4 GHz Intel Celeron?, 1 G Ram) and brought the machine up to Service Pack 3 with all other necessary updates from MS. The system was running nice and quick. Easily usable for internet access, office apps and other such things. Then I added Norton 2010. The full system scan is into it's 7th hour and has scanned only 44,885 items. How can this be? If this were a one time thing and from now on it would run faster then this may be acceptable but from some of the other posts I've seen this may be necessary weekly with little speed increase after this initial scan.

 

What about normal usage after this scan? How can I tell my sister-in-law that her machine is fine for everything except the virus scanner but since it is a necessary piece of software she has to buy a new laptop.

 

Can someone put my mind at ease that this initial scan always takes so long but after this it will run like a dream.

 

Thanks.

Brian