i would patch the boxes. you might be able to get away with just firewall, like tiny firewall. but sorry, you can't protect systems very well without trying to understand how these security threats work. unless you use shotgun approach of putting on all security patches (recommended!). otherwise you need to read up on how the threats work. microsoft has excellent security website with step by step instructions. also visit the os hardening tips at
www.cert.org. altho it is sure tempting to leave working systems alone...can you ghost them before you start, as backup? NT4 cannot be 'infected' by some of the recent worms but it can be attacked. also can cause lots of traffic on lan. maybe crippling. if servers are on your lan, how are they protected from network aware viruses that come into the lan from emails, from outside media? i would patch the boxes. ie4 will probably need updating also. get backed up first. check for lots of free, defragged hard disk space. have repair disks updated and ready.
