I ran into that more often that I thought I would back at the dialup/dsl techsupport job.

"my dad found this pc in a closet an gave it to us. we want to get online!"

Yes, there's sill 3.1. I know one particular bank around here that has one old machine that is still running windows 2.0. Yes two point oh. Meaning before 3.1. It's a beastly 386 with 16mb of ram and a 2gb hard drive. I don't know what it does, but all the people at the bank know is that it does something important and would cost $30k to get new software written for a new system. It's been working fine for 15 years or so. Had a few upgrades (ram and hard drive) over the years. Gets backed up everyday.

If it's not broken, dont' fix it.