Unattended...working at last

Looks like we're going to be getting a bunch more Windows desktops in the near future at $WORK, so I've been looking into Unattended again. I'm having much better luck this time than the last time I tried, a couple or three years ago.

I can't remember what went wrong then, but this time it took me a stupidly long time to figure out that an error message about a missing djgpp.env file means you forgot to unzip the support files under a directory called djgpp.

Another thing that tripped me up this time: unattended installations from OEM media are not allowed by default, even with a legit key from the sticker on the side of your new shiny box. This mailing list post pointed out the magic key, which seems to be working for mwe.

Now that I got those things sorted out, things are going much better.