We have a Win NT 4 server from the 90s that is still running. We outgrew the 20 GB hard drive (2 SCSI drives in a raid 1 array) and have a snap server 2200 with 250 GB (2 250s in a raid 1 array). 1 of the 2 hard drives in the win nt server has died a few weeks ago and we've kinda ignored it....
the NT box is really for authentication for the domain (but that's pointless since everyone has the same rights / no passwords / same username!) and runs backup exec to a tape drive.
I keep debating the benefits of pitching a new server to the boss... why not just get another hard drive? a few hundred bucks. vs.spending thousands on getting a new server, sbs 2003 (yeah, everyone uses outlook, the PSTs are on the snap server so they get backed up, and we have an outside hosting company.) and an extra 10 CALs (there's 13 users).
sharepoint, remote web workplace, OWA... nothing that people need / they are doing fine with the current arrangement for years now and boss would want to know why to spend thousands vs. hundreds