My first paid job where I had to use computers was as a graduate student. There I was using Macs.
If you count a brief consulting job, then running Linux on a Pentium 1.
If not, then running Windows NT 4.0 with no service packs, again on a Pentium 1. (Developing programs aimed at Windows 3.1 on 486 machines.)
Yeah, unlike the rest of you I spent a long time with no intention of getting into computers.
Cheers,
Ben