Lost Access to IE and Outlook

On my friend's W2000XP I was re-installing NAV + NAV
Internet Security and found a number of virus - which I
cleaned. At a point in the process Explore and Outlook
failed Outlook would not SEnd/Rec and Explore could not
find any pages.
However, I could access the NAV update site
update.symantec.com
Any ideas what has happened and what the process is from
now on??