Compaq did have a mandatory 2000 upgrade, but it was done in such a way to avoid problems. This was done with a combination of tools built to migrate people over to the new OS from previous Windows versions.

XP migrations wern't mandatory. I did an upgrade from the corporate files, and it worked rather well, since 2000 and XP are very similar under the hood. New PCs rolled out in the refresh program run XP.