scanning problem

Hi,

 

I have renewed and updated to norton anti virus 2010 installed on my computer and did a quick scan and everything fine as normal.  But when doing a full scan this works perfectly but then slows down after a while and still has not completed after 8 hours where previously it took around 45-60 mins to complete. 

 

Also when the guy from norton installed it he disabled my Windows firewall although NAV2010 dosen't seem to have this on it. Should i turn it on agaion or would it conflict with NAV?

 

 

Thanks for any help with these queries

 

Bangel