madodel wrote, apparently several years ago:
And what was the first operating system to have
builtin support for
internet access? Did Windows for Workgroups have this or was that just
LAN networking?
WfW 3.11 didn't include Internet support, it was an addon. Anyhow, WfW
3.11 wasn't introduced until 1993, while BSD 4.2 included Internet
support and was introduced in August 1983. BSD 4.1a had Internet
support, and was "released" in April 1982, but was not intended for wide
distribution. Since the IP-based Internet only came into existence on
January 1, 1983, it is unlikely that there were too many operating
systems with Internet support introduced earlier than BSD.
If you count support for ARPANET, the direct predecessor of the
Internet, TOPS-20AN existed at least as early as 1980.