No and no. You have to use a third party firewall. System restore was
first introduced with ME, after W2K was released, and then incorporated
into XP, W2K has no such feature.
Oh, I forgot to mention that one of your best defense against disasters
is to make sure that you have an up to date Emergency Repair Disk and
that you back up the registry at the same time that you create the ERD.
When you make major changes to Windows you should update the ERD.
That and a good backup strategy for your data.