Windows explorer not responding

Windows explorer and internet explorer recently just quit
responding. I can access the internet through my LAN
using Netscape Navigator and email through Outlook Express
but cannot open Internet Explorer and cannot open any
folder through windows explorer. I managed to correct
this once by reinstalling internet explorer in safe mode.
But, after downloading and intstalling the latest Windows
update, the same thing happened and I can't seem to get it
working again. System Restore does not help. I have
tried several restore points with no success.